Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2018	Mar. 01, 2019	Jun. 30, 2018
Document and Entity Information
Entity Registrant Name	CENTRUS ENERGY CORP
Entity Central Index Key	0001065059
Current Fiscal Year End Date	--12-31
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		9,437,389
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q4
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 17,800,000
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 123.1	$ 208.8
Accounts receivable, net	60.2	60.2
Inventories	129.7	153.1
Deferred costs associated with deferred revenue	134.9	122.3
Deposits for financial assurance	30.3	16.3
Other current assets	6.3	6.2
Total current assets	484.5	566.9
Property, Plant and Equipment, Net	4.2	4.9
Deposits for surety bonds	6.3	19.7
Intangible assets	76.0	82.7
Other long-term assets	0.7	1.1
Total Assets	571.7	675.3
Current Liabilities
Accounts payable and accrued liabilities	52.4	48.2
Payables under SWU purchase agreements	46.0	79.4
Inventories owed to customers and suppliers	103.0	77.9
Deferred revenue and advances from customers	204.5	191.8
Current debt	32.8	6.1
Total current liabilities	438.7	403.4
Long-term debt	120.2	157.5
Postretirement health and life benefit obligations	136.2	154.2
Pension benefit liabilities	168.9	161.6
Advances from customers	15.0	0.0
Other long-term liabilities	14.6	17.5
Total liabilities	893.6	894.2
Commitments and contingencies (Note 11)
Stockholders' Deficit
Excess of capital over par value	61.2	60.0
Accumulated deficit	(388.5)	(284.5)
Accumulated other comprehensive income (loss), net of tax	(0.1)	0.1
Total stockholders' deficit	(321.9)	(218.9)
Total Liabilities and Stockholders’ Equity (Deficit)	571.7	675.3
Preferred Series B [Member]
Stockholders' Deficit
Preferred stock	4.6	4.6
Common Class A [Member]
Stockholders' Deficit
Common stock	0.8	0.8
Common Class B [Member]
Stockholders' Deficit
Common stock	$ 0.1	$ 0.1

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	12 Months Ended
CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Preferred Stock, Par Value Per Share	$ 1.00	$ 1.00
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Shares Issued	104,574
Common Stock, Shares, Issued	9,437,389
Preferred Series B [Member]
Preferred Stock, Par Value Per Share	$ 1.00
Preferred Stock, Dividend Rate, Percentage	7.50%	7.50%
Preferred Stock, Shares Issued	104,574	104,574
Preferred Stock, Liquidation Preference, Value	$ 119,300,000	$ 111,500,000
Common Class A [Member]
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares Authorized	70,000,000	70,000,000
Common Stock, Shares, Issued	8,031,307	7,632,669
Common Class B [Member]
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares Authorized	30,000,000	30,000,000
Common Stock, Shares, Issued	1,406,082	1,406,082

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 193.0	$ 218.4
Cost of sales	210.9	188.2
Gross profit (loss)	(17.9)	30.2
Advanced technology license and decommissioning costs	26.1	15.7
Selling, general and administrative	39.9	43.7
Amortization of intangible assets	6.6	10.6
Special charges for workforce reductions and advisory costs	2.2	9.5
Other (income)	(0.3)	(4.6)
Operating (loss)	(92.4)	(44.7)
Gain on early extinguishment of debt	(0.5)	(33.6)
Nonoperating components of net periodic benefit expense (income)	10.6	(27.2)
Interest expense	4.1	5.3
Investment income	(2.5)	(1.3)
Income (loss) before income taxes	(104.1)	12.1
Provision (benefit) for income taxes	0.0	(0.1)
Net income (loss)	(104.1)	12.2
Preferred stock dividends, undeclared and cumulative	7.8	6.9
Net income (loss) allocable to common stockholders	$ (111.9)	$ 5.3
Net loss per share - basic and diluted	$ (12.23)	$ 0.58
Weighted-average number of shares outstanding:
Average number of common shares outstanding, basic and diluted	9,151	9,081
Weighted Average Number of Shares Outstanding, Diluted	9,151	9,081
Product [Member]
Cost of sales	$ 187.7	$ 162.7
Service [Member]
Cost of sales	$ 23.2	$ 25.5

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Net income (loss)	$ (104.1)	$ 12.2
Amortization of prior service costs (credits)	(0.2)	(0.1)
Other comprehensive income (loss), before tax	(0.2)	(0.1)
Income tax expense related to items of other comprehensive income	0.0	0.0
Other comprehensive income (loss), net of tax	(0.2)	(0.1)
Comprehensive income (loss)	$ (104.3)	$ 12.1

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash Flows from Operating Activities
Net income (loss)	$ (104.1)	$ 12.2
Adjustments to reconcile net income (loss) to net cash (used in) operating activities:
Depreciation and amortization	7.4	12.0
Immediate recognition of retirement benefit plans (gains) losses, net	17.3	(25.8)
Interest on paid-in-kind toggle notes	1.7	2.9
Gain on early extinguishment of debt	(0.5)	(33.6)
Gain on sale of assets	(0.4)	(4.6)
Changes in operating assets and liabilities:
Accounts receivable – (increase) decrease	9.7	(17.6)
Inventories, net – (increase) decrease	61.0	44.7
Payables under SWU purchase agreements – increase (decrease)	(33.4)	19.8
Deferred revenue, net of deferred costs – increase (decrease)	0.1	15.9
Accounts payable and other liabilities – increase (decrease)	3.7	(25.2)
Pension and postretirement liabilities - increase (decrease)	(28.0)	(9.6)
Other, net	(8.9)	(7.2)
Net Cash (Used in) Operating Activities	(74.4)	(16.1)
Cash Flows Provided by Investing Activities
Capital expenditures	(0.1)	(0.5)
Proceeds from sales of assets	0.5	4.7
Net Cash Provided by (Used in) Investing Activities	0.4	4.2
Cash Flows Used in Financing Activities
Payment of interest classified as debt	(6.1)	(3.4)
Repurchase of debt	(5.0)	(27.6)
Payment of securities transaction costs	0.0	(9.0)
Net Cash (Used in) Financing Activities	(11.1)	(40.0)
Decrease in cash, cash equivalents and restricted cash	(85.1)	(51.9)
Cash, cash equivalents and restricted cash, start of period	244.8	296.7
Cash, cash equivalents and restricted cash, end of period	159.7	244.8
Supplemental Cash Flow Information:
Interest paid	7.1	4.2
Conversion of interest payable-in-kind to long-term debt	1.7	0.4
Preferred Series B [Member]
Supplemental Cash Flow Information:
Exchange of debt for Series B preferred stock	$ 0.0	4.6
Common Class A [Member]
Supplemental Cash Flow Information:
Exchange of debt for Series B preferred stock		$ 0.0

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' DEFICIT - USD ($) $ in Millions	Total	Common Class A [Member]	Preferred Stock [Member]	Preferred Stock [Member] Preferred Series B [Member]	Common Stock [Member] Common Class A [Member]	Common Stock [Member] Common Class B [Member]	Excess of Capital over Par Value [Member]	Excess of Capital over Par Value [Member] Common Class A [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2016	$ (236.1)		$ 0.0		$ 0.8	$ 0.1	$ 59.5		$ (296.7)	$ 0.2
Net income (loss)	12.2								12.2
Stock issued during period	4.6		4.6
Other comprehensive income, net of tax (Note 17)	(0.1)									(0.1)
Restricted and other common stock issued, net of amortization	0.5						0.5
Ending Balance at Dec. 31, 2017	(218.9)		$ 4.6		0.8	0.1	60.0		(284.5)	0.1
Adoption of ASC 606 as of January 1, 2018 (Note 1)	0.1								0.1
Net income (loss)	(104.1)
Stock issued during period	0.8	$ 0.8						$ 0.8
Other comprehensive income, net of tax (Note 17)	(0.2)
Restricted and other common stock issued, net of amortization	0.4						0.4
Ending Balance at Dec. 31, 2018	$ (321.9)			$ 4.6	$ 0.8	$ 0.1	$ 61.2		$ (388.5)	$ (0.1)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies [Abstract]

Significant Accounting Policies

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Basis of Presentation and Principles of Consolidation

The consolidated financial statements of Centrus Energy Corp. (“Centrus” or the “Company”), which include the accounts of the Company, its principal subsidiary United States Enrichment Corporation (“Enrichment Corp.”) and its other subsidiaries, were prepared in conformity with generally accepted accounting principles in the U.S. (“U.S. GAAP”). Certain prior year amounts have been reclassified for consistency with the current year presentation. All material intercompany transactions have been eliminated.

Correction of Error

In the second quarter of 2018, Management identified a classification error for $0.3 million of costs that had been previously included in Cost of Sales for the contract services segment in the consolidated statement of operations for the three months ended March 31, 2018. These costs are now included in Advanced Technology License and Decommissioning Costs in the consolidated statement of operations for the year ended December 31, 2018. The Company considered quantitative and qualitative factors in assessing the materiality of the classification error and determined that the classification error was not material. This revision had no impact to the Company’s net loss for the three months ended March 31, 2018, or the year ended December 31, 2018.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect reported amounts presented and disclosed in the consolidated financial statements. Significant estimates and judgments include, but are not limited to, asset valuations, pension and postretirement health and life benefit costs and obligations, the tax bases of assets and liabilities, the future recoverability of deferred tax assets, and determination of the valuation allowance for deferred tax assets. Actual results may differ from such estimates, and estimates may change if the underlying conditions or assumptions change.

Cash and Cash Equivalents

Cash and cash equivalents include short-term or highly liquid assets with original maturities of three months or less.

Inventories and Inventories Owed to Customers and Suppliers

Low-enriched uranium (“LEU”) consists of two components: separative work units (“SWU”) and uranium. SWU is a standard unit of measurement that represents the effort required to transform a given amount of natural uranium into two components: enriched uranium having a higher percentage of U²³⁵ and depleted uranium having a lower percentage of U²³⁵. The SWU contained in LEU is calculated using an industry standard formula based on the physics of enrichment. The amount of enrichment deemed to be contained in LEU under this formula is commonly referred to as its SWU component and the quantity of natural uranium deemed to be used in the production of LEU under this formula is referred to as its uranium or “feed” component.

SWU and uranium inventory costs are determined using the average cost method. SWU and uranium purchase costs include shipping costs when applicable. Inventories of SWU and uranium are valued at the lower of cost or net realizable value (“NRV”). NRV is the estimated selling price in the ordinary course of business less reasonably predictable costs of completion, disposal, and transportation. The estimated selling price for SWU and uranium is based on the pricing terms of contracts in the Company’s sales order book, and, for uranium not under contract, the estimated selling price is based primarily on published price indicators at the balance sheet date.

Inventories owed to customers and suppliers, included in current liabilities, consist primarily of SWU and uranium inventories owed to fabricators. Fabricators process LEU into fuel for use in nuclear reactors. Under inventory optimization arrangements between Centrus and domestic fabricators, fabricators order quantities of LEU from Centrus based on scheduled or anticipated orders from utility customers for deliveries in future periods. As delivery obligations under actual customer orders arise, Centrus satisfies these obligations by arranging for the transfer to the customer of title to the specified quantity of LEU at the fabricator. Centrus’ balances of SWU and uranium vary over time based on the timing and size of the fabricator’s LEU orders from Centrus and the fabricator’s needs for working stock of LEU. Balances can be positive or negative at the discretion of the fabricator. Fabricators have other inventory supplies and, where a fabricator has elected to order less material from Centrus than Centrus is required to deliver to its customers at the fabricator, the fabricator will use these other inventories to satisfy Centrus’ customer order obligations on Centrus’ behalf. In such cases, the transfer of title of LEU from Centrus to the customer results in quantities of SWU and uranium being owed by Centrus to the fabricator. The amounts of SWU and uranium owed to fabricators are satisfied as future deliveries of LEU to fabricators are made.

Deferred Taxes

Centrus follows the asset and liability approach to account for deferred taxes. Deferred tax assets and liabilities are recognized for the anticipated future tax consequences of temporary differences between the balance sheet carrying amounts of assets and liabilities and their respective tax bases. Deferred taxes are based on income tax rates in effect for the years in which temporary differences are expected to reverse. The effect on deferred taxes of a change in income tax rates is recognized in income when the change in rates is enacted in the law. A valuation allowance is provided if it is more likely than not that all, or some portion, of the deferred tax assets may not be realized.

Property, Plant and Equipment

Property, plant and equipment are recorded at acquisition cost. Leasehold improvements and machinery and equipment are depreciated on a straight-line basis over the shorter of the useful life of the assets or the lease term, if applicable. Refer also to Carrying Value of Long-Lived Assets below.

Intangible Assets

Centrus has intangible assets resulting from fresh start accounting as a result of emergence from Chapter 11 bankruptcy on September 30, 2014. The identifiable intangible assets relate to the sales order book and customer relationships. The order book intangible asset is amortized as the order book valued at emergence is reduced, principally as a result of deliveries to customers. The customer relationships intangible asset is amortized using the straight-line method over the estimated average useful life of 15 years. Refer also to Carrying Value of Long-Lived Assets below.

Carrying Value of Long-Lived Assets

The Company evaluates the carrying values of property, plant and equipment and identifiable intangible assets when events or changes in business circumstances indicate that the carrying amount of asset, or asset group, may not be fully recoverable. The carrying amount of a long-lived asset is not recoverable if it exceeds the sum of the undiscounted cash flows expected to result from the use and eventual disposition of the asset. An impairment loss is measured as the amount by which the carrying amount of a long-lived asset, or asset group exceeds its fair value.

Financial Instruments and Fair Value Measurement

Accounting standards define fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, consideration is given to the principal or most advantageous market and assumptions that market participants would use when pricing the asset or liability.

Pursuant to accounting standards, Centrus’ 8.0% paid-in-kind (“PIK”) toggle notes (the “8% PIK Toggle Notes”) and its 8.25% notes (the “8.25% Notes”) are recorded at face value and the fair value is disclosed. The estimated fair value of each of the 8% PIK Toggle Notes and the 8.25% Notes is based on the trading price nearest the balance sheet date observed on secondary markets. Debt issuance costs are deferred and amortized over the life of the instrument.

The balance sheet carrying amounts for accounts receivable, accounts payable and accrued liabilities, and payables under SWU purchase agreements approximate fair value because of the short-term nature of the instruments.

Concentrations of Credit Risk

Credit risk could result from the possibility of a customer failing to perform or pay according to the terms of a contract. Extension of credit is based on an evaluation of each customer’s financial condition. Centrus regularly monitors credit risk exposure and takes steps to mitigate the likelihood of such exposure resulting in a loss.

Revenue

On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method as applied to customer contracts that were not completed as of the adoption date. As a result, financial information for reporting periods beginning on or after January 1, 2018, are presented under ASC 606, while comparative financial information has not been adjusted and continues to be reported in accordance with the Company’s historical accounting policy for revenue recognition prior to the adoption of ASC 606. There was no material impact of adopting ASC 606 for sales under the LEU segment. For sales under the contract services segment, revenue is now primarily recognized over time as control is transferred to the customer.

Revenue for product and service sales is recognized when or as the Company transfers control of the promised products or services to the customer. Revenue is measured at the transaction price, which is based on the amount of consideration that the Company expects to receive in exchange for transferring the promised goods or services to the customer. The transaction price will include estimates of variable consideration to the extent it is probable that a significant reversal of revenue recognized will not occur.

SWU and Uranium Revenue

Revenue for the Company’s LEU segment is derived from sales of the SWU component of LEU, from sales of both the SWU and uranium components of LEU, and from sales of uranium. Contracts with customers are primarily long-term, fixed-commitment contracts under which its customers are obligated to purchase a specified quantity of the SWU component of LEU or the SWU and uranium components of LEU. The Company’s contracts for natural uranium are generally shorter-term, fixed-commitment contracts.

Revenue is recognized at the time the customer obtains control of the LEU or uranium. Customers generally obtain control of LEU at nuclear fuel fabricators. Centrus ships LEU to nuclear fuel fabricators for scheduled or anticipated orders from utility customers. Based on customer orders, Centrus arranges for the transfer of title of LEU from Centrus to the customer for the specified quantity of LEU at the fuel fabricator. Each such delivery to a customer is accounted for as a distinct performance obligation under a contract, and a contract may call for multiple deliveries over a number of periods. The contract’s transaction price is allocated to each performance obligation based on the observable standalone selling price of each distinct delivery of SWU or uranium.

Utility customers in general have the option to defer receipt of LEU or uranium purchased from the Company beyond the contractual sale period. In such cases, title to LEU or uranium is transferred to the customer and a performance obligation for Centrus is created and a receivable is recorded. Cash is collected for the receivable under normal credit terms. The performance obligation is represented as Deferred Revenue on the consolidated balance sheet and the customer-titled product is classified as Deferred Costs Associated with Deferred Revenue on the consolidated balance sheet. Risk of loss remains with Centrus until the customer obtains control of LEU or uranium. The recognition of revenue and related cost of sales occurs at the point in time at which the customer obtains control of LEU or uranium and risk of loss of the product transfers to the customer, which may occur beyond one year. The timing of the transfer of control, subject to notice period requirements, is at the option of the customer. As such, deferred costs and deferred revenue are classified within current assets and current liabilities, respectively.

On occasion, the Company will accept payment in the form of uranium. Revenue from the sale of SWU under such contracts is recognized at the time transfer of control of LEU occurs and is based on the fair value of the uranium at contract inception or as the quantity of uranium is finalized, if variable. The Company may also borrow SWU from customers, in which case the Company will record the SWU and the related liability for the borrowing using a projected average purchase price over the borrowing period.

Amounts billed to customers for handling costs are included in sales. Handling costs are accounted for as a fulfillment cost and are included in cost of sales. The Company does not have shipping costs associated with outbound freight after control over a product has transferred to a customer. The Company’s contracts with customers do not provide for significant payment terms or financing components.

Contract Services Revenue

Revenue for the contract services segment, principally representing engineering and testing activities performed by the Company, as well as technical and resource support, is recognized over the contractual period as services are rendered. The Company recognizes revenue over time as it performs on these contracts because of the continuous transfer of control to the customer. With control transferring over time, revenue is recognized based on the extent of progress towards completion of the performance obligation. A contract may contain one or more performance obligations. Two or more promises to transfer goods or services to a customer may be considered a single performance obligation if the goods or services are highly interdependent or highly interrelated such that utility of the promised goods or services to the customer includes integration services provided by the Company.

The Company generally uses the cost-to-cost input method of progress for fixed-price contracts because it best depicts the transfer of control to the customer that occurs as the Company incurs costs. Under the cost-to-cost method, the extent of progress towards completion is measured based on the proportion of direct costs incurred to date to the total estimated direct costs at completion of the performance obligation. Revenues are recorded proportionally as costs are incurred. If transaction prices are not stated in the contract for each performance obligation, contractual prices are allocated to performance obligations based on estimated relative standalone selling prices of the promised services. For contracts that are not accounted for under the percentage of completion method, the Company records revenue as services are provided. The Company recognizes time-and-material contract revenue at negotiated, fixed, contractually billable rates as it delivers labor hours and incurs other direct expenses.

The Company has applied the practical expedient in paragraph ASC 606-10-50-14 and does not provide the value of remaining performance obligations under service contracts having original expected terms of one year or less.

The timing of revenue recognition may differ from the timing of invoicing to customers. Progress on satisfying performance obligations under contracts with customers and the related billings and cash collections are recorded on the consolidated balance sheet as contract assets or contract liabilities. Contract balances are classified as assets or liabilities on a contract-by-contract basis at the end of each reporting period.

Unbilled receivables (contract assets) are included in Accounts Receivable on the consolidated balance sheet and arise when the timing of cash collected from customers differs from the timing of revenue recognition, such as when contract provisions require specific milestones to be met before a customer can be billed. Those assets are recognized when the revenue associated with the contract is recognized prior to billing and derecognized when billed in accordance with the terms of the contract. To the extent billings to the customer precede the recognition of contract services revenue, the Company recognizes a liability included in Deferred Revenue and Advances from Customers on the consolidated balance sheet.

Results for prior periods were reported in accordance with ASC 605. Revenue derived from sales of the SWU component of LEU, from sales of both the SWU and uranium components of LEU, and from sales of uranium was recognized at the time LEU or uranium was delivered under the terms of contracts with domestic and international electric utility customers. Most customers took title and delivery of LEU at fuel fabricators and revenue was recognized when delivery of LEU to the customer occurred at the fuel fabricator. In cases when utility customers deferred receipt of LEU or uranium purchased from the Company beyond the contractual sale period, title to LEU or uranium was transferred to the customer and risk of loss remained with Centrus until delivery occurred. The recognition of revenue and related cost of sales occurred at the time delivery occurred and risk of loss transferred to the customer. In cases where Centrus accepted payment in the form of uranium, revenue was recognized at the time LEU was delivered and was based on the fair value of the uranium received in exchange for the SWU.

Contract services revenue in prior periods included billings for fees and payments for allowable costs that were determined in accordance with the terms of the underlying contracts. For contracts that provided fixed payments for monthly reports, revenue was recognized as deliverables are completed and as fees are earned. For contracts that provided fixed payments for completion of milestones, revenue was recognized as each milestone is completed.

Advanced Technology License and Decommissioning Costs

American Centrifuge expenses that are outside of our contracts with UT-Battelle are included in Advanced Technology License and Decommissioning Costs, including ongoing costs to maintain the demobilized Piketon facility and our licenses from the U.S. Nuclear Regulatory Commission (“NRC”) at that location. Refer to Note 16, Commitments and Contingencies, for further details regarding the American Centrifuge project.

Pension and Postretirement Health and Life Benefit Plans

The Company provides retirement benefits to certain employees and retirees under defined benefit pension plans and postretirement health and life benefit plans. The valuation of benefit obligations and costs is based on provisions of the plans and actuarial assumptions that involve judgments and estimates. Plan assets and benefit obligations are remeasured each year as of the balance sheet date, or when lump sum payments exceed certain levels, resulting in differences between actual and projected results. The Company has elected to recognize these actuarial gains and losses immediately in the statement of operations to provide transparency regarding the impacts of changes in plan assets and benefit obligations.

Stock-Based Compensation

Centrus has a stock-based compensation plan which authorizes the issuance of common stock to the Company’s employees, officers, directors and other individuals providing services to the Company or its affiliates pursuant to options, stock appreciation rights, restricted stock units, restricted stock, performance awards, dividend equivalent rights and other stock based awards. Stock-based compensation cost is measured at the grant date based on the fair value of the award. The cost is recognized over the requisite service period on a straight-line basis over the vesting period.

New Accounting Standards

Recently Adopted Accounting Standards

In 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers, which requires revenue to be recognized when a customer obtains control of promised goods and services at an amount that reflects the consideration the Company expects to receive in exchange for those goods and services. In addition, ASU 2014-09 and subsequent amendments, collectively known as Accounting Standards Codification (“ASC”) 606 (“ASC 606”) require certain additional disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers.

The Company adopted ASC 606 on January 1, 2018, using the modified retrospective method. The new standard was applied to contracts that were not completed as of the adoption date. The Company recognized the cumulative effect of initially applying ASC 606 of $0.1 million as an adjustment to the opening balance of accumulated deficit. The comparative information has not been restated and continues to be presented according to accounting standards in effect for those periods. Refer to Note 2, Revenue and Contracts with Customers, for additional information.

The following table summarizes the cumulative effect of the changes to the Company’s consolidated balance sheet as of January 1, 2018, from the adoption of ASC 606 (in millions):



	Balance at December 31, 2017			Adjustment for ASC 606		Balance at January 1, 2018
Assets:
Unbilled contract revenue	$	—		$	0.1	$	0.1
Stockholders’ Deficit:
Accumulated Deficit	(284.5		)	0.1		(284.4		)

The following table summarizes the impact of adopting ASC 606 on revenue and net loss for the year ended December 31, 2018 (in millions):



	Year Ended December 31, 2018
	As Reported			Under Previous Accounting			Effect of Adoption
Revenue	$	193.0		$	193.1		$	(0.1	)
Net loss	(104.1		)	(104.0		)	(0.1		)

The effect of adoption for the year ended December 31, 2018, includes the opening balance adjustment of $0.1 million.

In March 2017, the FASB issued ASU 2017-07, Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost. ASU 2017-07 requires changes to the presentation of the components of net periodic benefit cost on the statement of operations by requiring service cost to be presented with other employee compensation costs and other components of net periodic benefit cost to be presented outside of any subtotal of operating income. The Company adopted this standard on January 1, 2018, on a retrospective basis for all periods presented, and certain prior period amounts have been recast to conform with the current presentation as follows (in millions):



	Year Ended December 31, 2017
	As Previously Reported		Adjustments			Current Presentation
Cost of sales - separative work units and uranium	$	136.1	$	26.6		$	162.7
Selling, general and administrative	43.1		0.6			43.7
Nonoperating components of net periodic benefit expense (income)	—		(27.2		)	(27.2		)

Refer to Note 11, Pension and Postretirement Health and Life Benefits, for additional information.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments. ASU 2016-15 addresses the presentation and classification of certain cash receipts and cash payments in the statement of cash flows. It is intended to reduce diversity in practice by providing guidance on eight specific cash flow issues. ASU 2016-15 became effective for the Company on January 1, 2018. Upon adoption, the Company reclassified $9.0 million of transaction costs incurred in the first quarter of 2017 related to the note exchange (see Note 9, Debt) in the statement of cash flows as follows (in millions):



	Year Ended December 31, 2017
	As Previously Reported			Adjustments			Current Presentation
Cash used in operating activities	$	(25.1	)	$	9.0		$	(16.1	)
Cash used in financing activities	(31.0		)	(9.0		)	(40.0		)

In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash. ASU 2016-18 requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. ASU 2016-18 is to be applied retrospectively for each period presented. The Company adopted the new standard on January 1, 2018. Upon adoption, the Company added its restricted cash balances to the consolidated statement of cash flows, and the prior period amounts have been recast to conform with the current presentation.

In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory, requiring the recognition of the current and deferred income taxes resulting from an intra-entity transfer of assets other than inventory when the transfer occurs. The Company adopted the new standard on January 1, 2018, on a modified retrospective basis. The adoption of ASU 2016-16 did not have a material impact on the Company’s consolidated financial statements, including the cumulative effect adjustment required upon adoption.

Accounting Standards Effective in Future Periods

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which requires lessees to recognize a right-of-use asset and lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will be classified as either financing or operating, with classification affecting expense recognition in the statement of operations. The standard is effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. The new guidance, as amended in July 2018 by ASU 2018-11, Leases (Topic 842): Targeted Improvements, requires a transition adoption election using either 1) a modified retrospective approach with periods prior to the adoption date being recast or 2) a prospective adoption approach with a cumulative-effect adjustment recognized to the opening balance of retained earnings on the adoption date with prior periods not recast. The Company is finalizing its evaluation of the impact of adoption and anticipates adopting this standard as of January 1, 2019, using the prospective adoption approach.

In February 2018, the FASB issued ASU 2018-02, Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in ASU 2018-02 allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cut and Jobs Act of 2017 (the “Tax Act”). However, because the amendments only relate to the reclassification of the income tax effects of the Tax Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The amendments in ASU 2018-02 are effective for all entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early adoption of the amendments is permitted. The Company is currently evaluating the effect of the standard on its Consolidated Financial Statements.

In August 2018, the FASB issued ASU 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20), which modifies the disclosure requirements for employers that sponsor defined benefit pension plans and other postretirement plans. ASU 2018-14 is effective for public companies for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. The standard is to be applied on a retrospective basis to all periods presented and early adoption is permitted. The Company is evaluating the effect that the provisions of ASU 2018-14 will have on its consolidated financial statements.

Revenue and Contracts with Customers

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Revenue from Contract with Customer

REVENUE AND CONTRACTS WITH CUSTOMERS

Disaggregation of Revenue

The following table presents revenue from SWU and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):



	Year Ended December 31,
	2018		2017
United States	$	112.7	$	111.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Revenue - SWU and uranium	$	164.4	$	195.4

Refer to Note 18, Revenue by Geographic Area, Major Customers and Segment Information for disaggregation of revenue by segment. Disaggregation by end-market is provided in Note 18 and the consolidated statements of operations. SWU and uranium sales are made primarily to electric utility customers. Contract services revenue resulted primarily from services provided to government contractors and, in the first quarter of 2018, the settlement with DOE and the U.S. government. SWU and uranium revenue is recognized at point of sale and contract services revenue is generally recognized over time.

Contract Balances

The following table represents changes in the Company’s contract assets and contract liabilities balances (in millions):



	December 31, 2018		January 1, 2018		Year-To-Date Change
Contract assets
Accounts receivable:
Billed	$	50.4	$	60.2	$	(9.8	)
Uranium feed receivable	9.8		—		9.8
Unbilled contract revenue	—		0.1		(0.1		)
Accounts receivable	$	60.2	$	60.3	$	(0.1	)

Deferred costs associated with deferred revenue	$	134.9	$	122.3	$	12.6

Contract liabilities
Deferred revenue and advances from customers - current:
Deferred revenue	$	204.5	$	172.5	$	32.0
Advances from customers	—		19.3		(19.3		)
Deferred revenue and advances from customers - current	$	204.5	$	191.8	$	12.7

Advances from customers - noncurrent	$	15.0	$	—	$	15.0

Deferred cost and deferred revenue activity for the year ended December 31, 2018, follows (in millions):



	Deferred Sales in the Period		Previously Deferred Sales Recognized in the Period			Year-To-Date Change
Deferred costs associated with deferred revenue	$	25.4	$	(12.8	)	$	12.6
Deferred revenue	55.3		(23.3		)	32.0

In the second quarter of 2018, the Company received uranium valued at $14.5 million from a customer that elected to defer a SWU purchase obligation for a period greater than one year. Under the contract, the customer has not received title to SWU or LEU product from the Company. The liability to the customer is included in Advances from Customers, a noncurrent liability. In December 2018, the Company borrowed $7.3 million of SWU from a customer under terms which require repayment within 48 months. The Company recorded the SWU and the related liability for the borrowing using an average purchase price over the borrowing period. The liability to the customer is included in Other Liabilities, which is included in noncurrent liabilities.

On January 11, 2018, the Company entered into a settlement agreement with DOE and the U.S. government regarding breach of contract claims relating to work performed by the Company under contracts with DOE and subcontracts with DOE contractors. DOE agreed to settle all claims raised as part of and subsequent to the litigation, except with respect to certain claims for pension and postretirement benefits, for a total of $24.0 million and provide a complete close out of all such contracts and subcontracts settled under the settlement agreement without any further audit or review of the Company’s costs or incurred cost submissions. Prior to the settlement, the Company had a receivables balance related to the claims being settled of $14.5 million. In 2018, the Company (a) received $4.7 million from the U.S. government, (b) applied approximately $19.3 million of advances from the U.S. government received in prior years against the receivables balance, and (c) recorded additional revenue of $9.5 million.

Centrus and DOE have yet to fully settle the Company’s claims for reimbursements for certain pension and postretirement benefits costs related to past contract work performed for DOE. There is the potential for additional revenue to be recognized for this work pending the outcome of legal proceedings related to the Company’s claims for payment and the potential release of previously established valuation allowances on receivables. As a result of the application of fresh start accounting following the Company’s emergence from Chapter 11 bankruptcy on September 30, 2014, the receivables related to the Company’s claims for payment are carried at fair value as of September 30, 2014, which is net of the valuation allowances.

LEU Segment Order Book

The SWU component of LEU is typically bought and sold under long-term contracts with deliveries over several years. The Company’s agreements for natural uranium sales are generally shorter-term, fixed-commitment contracts. The Company’s order book sales under contract in the LEU segment (“order book”) extends to 2030. The order book represents the Company’s remaining performance obligations under these contracts and includes the Deferred Revenue amounts in the Contract Balances table above. The order book was $1.0 billion as of December 31, 2018, compared to $1.3 billion at December 31, 2017, reflecting completed deliveries and new contracts signed in 2018 and a rejection of a contract by a customer in bankruptcy proceedings. No other adjustments were required to the Company’s consolidated financial statements as a result of the contract rejection. Refer to Note 16, Commitments and Contingencies, for additional information regarding the customer and claims filed by the Company.

Most of the Company’s contracts provide for fixed purchases of SWU during a given year. The Company’s estimate of the aggregate dollar amount of future SWU and uranium sales is partially based on customers’ estimates of the timing and size of their fuel requirements and other assumptions that are subject to change. For example, depending on the terms of specific contracts, the customer may be able to increase or decrease the quantity delivered within an agreed range. The Company’s order book estimate is also based on the Company’s estimates of selling prices, which are subject to change. For example, depending on the terms of specific contracts, prices may be adjusted based on escalation using a general inflation index, published SWU price indicators prevailing at the time of delivery, and other factors, all of which are variable. The Company uses external composite forecasts of future market prices and inflation rates in its pricing estimates.

Contract Modification

In 2018 the Company entered into an arrangement with a fabricator to facilitate a prior arrangement with a customer that resulted in a modification of its previous SWU sales arrangement with the customer. The product to be delivered under the modified arrangement is distinct and, therefore, the modification is being accounted for on a prospective basis. No revenue was recognized in 2018 from the customer as the distinct product was not delivered. Under the new arrangement, the Company made a payment to the customer of $20.7 million that is a contract asset, which will be recovered as payments are received from the customer for the remaining product delivery. The Company received $21.1 million in December 2018 that is a contract liability and the net of these amounts of $0.4 million is classified as a contract liability as of December 31, 2018, which is included in Advances from Customers, a noncurrent liability.

Special Charges

12 Months Ended

Dec. 31, 2018

Restructuring and Related Activities [Abstract]

Special Charges

SPECIAL CHARGES

For the years ended December 31, 2018 and 2017, special charges totaled $2.2 million and $9.5 million, respectively, including advisory costs of $0.1 million and $6.3 million, respectively. In 2018 and 2017, advisory costs related to updating the Company’s information technology systems.

Workforce reductions have resulted from evolving business needs and the completion of the demonstration of American Centrifuge technology at the Company’s facility in Piketon, Ohio. Without mutual agreement between Centrus and DOE regarding other possible uses for the Piketon facility, the remaining balance of termination benefits of $3.2 million related to the Piketon facility is expected to be paid in the third quarter of 2019 and is classified in Accounts Payable and Accrued Liabilities in the consolidated balance sheet. A summary of termination benefit activity and related liabilities follows (in millions):



	Liability Dec. 31, 2016		2017					Liability Dec. 31, 2017		2018					Liability Dec. 31, 2018
	Liability Dec. 31, 2016		Charges for Termination Benefits		Paid/ Settled			Liability Dec. 31, 2017		Charges for Termination Benefits		Paid/ Settled			Liability Dec. 31, 2018
Workforce reductions:
Evolving business needs	$	0.1	$	2.4	$	(1.7	)	$	0.8	$	2.1	$	(2.0	)	$	0.9
Piketon demonstration facility	5.4		1.1		(0.8		)	5.7		0.1		(2.6		)	3.2
Total	$	5.5	$	3.5	$	(2.5	)	$	6.5	$	2.2	$	(4.6	)	$	4.1

Cash, Cash Equivalents and Restricted Cash

12 Months Ended

Dec. 31, 2018

Cash, Cash Equivalents and Restricted Cash [Abstract]

Cash and Cash Equivalents Disclosure

CASH, CASH EQUIVALENTS AND RESTRICTED CASH

The following table summarizes the Company’s cash, cash equivalents and restricted cash as presented on the consolidated balance sheet to amounts on the consolidated statement of cash flows (in millions):



	December 31, 2018		December 31, 2017

Cash and cash equivalents	$	123.1	$	208.8
Deposits for financial assurance - current	30.3		16.3
Deposits for financial assurance - noncurrent	6.3		19.7
Total cash, cash equivalents and restricted cash	$	159.7	$	244.8

The following table provides additional detail regarding the Company’s deposits for financial assurance (in millions):



	December 31, 2018				December 31, 2017
	Current		Long-Term		Current		Long-Term
NRC license	$	16.3	$	—	$	16.1	$	—
DOE lease	13.8		—		—		13.5
Workers compensation	—		6.0		—		5.9
Other	0.2		0.3		0.2		0.3
Total deposits for financial assurance	$	30.3	$	6.3	$	16.3	$	19.7

Piketon Facility Obligations and Surety Bonds

Centrus commenced with the decontamination and decommissioning (“D&D”) of the Piketon demonstration facility in accordance with the NRC license requirements in 2016. Centrus has previously provided financial assurance to the NRC for the D&D work in the form of surety bonds that are fully cash collateralized by Centrus for $16.3 million. Centrus believes the D&D work required for elimination of financial assurance under NRC license requirements has been completed and is working with the NRC to have the surety bonds cancelled, which would permit the Company to receive the cash collateral.

Centrus leases the Piketon facility from DOE. At the conclusion of the lease on June 30, 2019, absent mutual agreement between Centrus and DOE regarding other possible uses for the facility, Centrus is obligated to return the facility to DOE in a condition that meets NRC license requirements and in the same condition as the facility was in when it was leased to Centrus (other than due to normal wear and tear). Centrus must remove all Company-owned capital improvements at the Piketon facility, unless otherwise consented to by DOE, by the conclusion of the lease term. The estimated cost for these lease termination obligations, included in Accounts Payable and Accrued Liabilities on the consolidated balance sheet, is $1.6 million and $0.8 million as of December 31, 2018, and December 31, 2017, respectively. Centrus has previously provided financial assurance to DOE for the lease turnover obligations in the form of surety bonds that are fully cash collateralized by Centrus for $13.8 million. Centrus expects to receive cash when these surety bonds are reduced and/or cancelled as the Company fulfills its lease turnover obligations.

Financial Assurance for Workers’ Compensation

The Company has provided financial assurance to states in which it was previously self-insured for workers’ compensation in accordance with the state requirements in the form of a surety bond and a letter of credit that are fully cash collateralized by Centrus for $6.0 million. The surety bond and letter of credit will be cancelled, and the Company expects to receive cash when each state determines the Company has no further workers’ compensation obligations.

Property, Plant and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

PROPERTY, PLANT AND EQUIPMENT

A summary of changes in property, plant and equipment follows (in millions):



	December 31, 2017			Additions / (Depreciation)			Retirements			December 31, 2018
Land	$	1.2		$	—		$	—		$	1.2
Leasehold improvements	3.2			—			(0.7		)	2.5
Machinery and equipment	1.3			0.1			(0.4		)	1.0
Other	1.1			—			—			1.1
Property, plant and equipment, gross	6.8			0.1			(1.1		)	5.8
Accumulated depreciation	(1.9		)	(0.8		)	1.1			(1.6		)
Property, plant and equipment, net	$	4.9		$	(0.7	)	$	—		$	4.2

Depreciation expense was $0.8 million and $1.4 million for the years ended December 31, 2018 and 2017, respectively.

The Company sold assets and property in 2018 and 2017 related to its operations and the American Centrifuge project that were no longer needed (in millions):



	Year Ended December 31,
	2018		2017
Sales of assets and property, net of auction fees and other costs	$	0.4	$	4.8
Less: net carrying value	—		(0.2		)
Gain on sales of assets	$	0.4	$	4.6

Cash proceeds received	$	0.5	$	4.7

Cash proceeds for the years ended December 31, 2018 and 2017 include $0.1 million and $0.2 million, respectively, which were included in Accounts Receivable as of December 31 of the prior year.

Intangible Assets

12 Months Ended

Dec. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Intangible Assets

INTANGIBLE ASSETS

Intangible assets originated from the Company’s reorganization and application of fresh start accounting as of the date the Company emerged from bankruptcy, September 30, 2014, and reflect the conditions at that time. The intangible asset related to the sales order book is amortized as the order book existing at emergence is reduced, principally as a result of deliveries to customers. The intangible asset related to customer relationships is amortized using the straight-line method over the estimated average useful life of 15 years. Amortization expense is presented below gross profit on the consolidated statements of operations. Intangible asset balances are as follows (in millions):



	December 31, 2018						December 31, 2017

	Gross Carrying Amount		Accumulated Amortization		Net Amount		Gross Carrying Amount		Accumulated Amortization		Net Amount
Sales order book	$	54.6	$	28.0	$	26.6	$	54.6	$	25.9	$	28.7
Customer relationships	68.9		19.5		49.4		68.9		14.9		54.0
Total	$	123.5	$	47.5	$	76.0	$	123.5	$	40.8	$	82.7

The amount of amortization expense for intangible assets in each of the succeeding years is estimated to be as follows (in millions):



2019	$	5.4
2020	8.0
2021	8.8
2022	9.7
2023	8.3
Thereafter	35.8
Total	$	76.0

Debt

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Debt

DEBT

A summary of debt follows (in millions):



		December 31, 2018				December 31, 2017
	Maturity	Current		Long-Term		Current		Long-Term
8.25% Notes:	Feb. 2027
Principal		$	—	$	74.3	$	—	$	74.3
Interest		6.1		45.9		6.1		52.0
8.25% Notes		$	6.1	$	120.2	$	6.1	$	126.3

8% PIK Toggle Notes	Sep. 2019^(a)	$	26.7	$	—	$	—	$	31.3
Less deferred issuance costs		—		—		—		0.1
8% PIK Toggle Notes		$	26.7	$	—	$	—	$	31.2

Total		$	32.8	$	120.2	$	6.1	$	157.5

(a) Maturity can be extended to September 2024 upon the satisfaction of certain funding conditions described in the applicable indenture.

December 6, 2018 Note Exchange

On December 6, 2018, Centrus entered into Exchange Agreements (the “Exchange Agreements”) with certain holders of the Company’s outstanding 8% PIK Toggle Notes. Under the terms of the Exchange Agreements, the Company exchanged $6.3 million aggregate principal amount of 8% PIK Toggle Notes for 398,638 shares of Class A Common Stock and approximately $5.1 million in cash, which included accrued and unpaid interest on the Notes. The Company recognized a gain on extinguishment of $0.5 million, which is net of transaction costs and previously deferred costs related to the 8% PIK Toggle Notes of less than $0.1 million. Refer to Note 15, Stockholders’ Equity for details related to the common stock.

February 14, 2017 Note Exchange

On February 14, 2017, pursuant to an exchange offer and consent solicitation, Centrus exchanged $204.9 million principal amount of the Company’s 8% PIK Toggle Notes for $74.3 million principal amount of 8.25% notes due February 2027 (the “8.25% Notes”), 104,574 shares of Series B Preferred Stock with a liquidation preference of $1,000 per share, and $27.6 million of cash. The exchange is accounted for as a troubled debt restructuring under ASC Subtopic 470-60, Debt-Troubled Debt Restructurings by Debtors. The Company recognized the 8.25% Notes on the consolidated balance sheet as the sum of the principal balance and all future interest payments and recognized a gain of $33.6 million related to the note exchange for the quarter ended March 31, 2017, which is net of transaction costs of $9.0 million and previously deferred issuance costs related to the 8% PIK Toggle Notes of $0.4 million. Refer to Note 15, Stockholders’ Equity for details related to the preferred stock.

8.25% Notes

Interest on the 8.25% Notes is payable semi-annually in arrears as of February 28 and August 31 based on a 360-day year consisting of twelve 30-day months. The 8.25% Notes mature on February 28, 2027. As described above, all future interest payment obligations on the 8.25% Notes are included in the carrying value of the 8.25% Notes. As a result, the Company’s reported interest expense will be less than its contractual interest payments throughout the term of the 8.25% Notes. As of December 31, 2018, and December 31, 2017, $6.1 million of interest is recorded as current and classified as Current Debt in the consolidated balance sheet.

The 8.25% Notes rank equally in right of payment with all of the Company’s existing and future unsubordinated indebtedness other than its Issuer Senior Debt and our Limited Secured Acquisition Debt (each as defined below). The 8.25% Notes rank senior in right of payment to all of the Company’s existing and future subordinated indebtedness and to certain limited secured acquisition indebtedness of the Company (the “Limited Secured Acquisition Debt”). The Limited Secured Acquisition Debt includes (i) any indebtedness, the proceeds of which are used to finance all or a portion of an acquisition or similar transaction if any lender’s lien is solely limited to the assets acquired in such a transaction and (ii) any indebtedness, the proceeds of which are used to finance all or a portion of the American Centrifuge project or another next generation enrichment technology if any lender’s lien is solely limited to such assets, provided that a lien securing the 8.25% Notes that is junior with respect to the lien securing such indebtedness will be limited to the assets acquired with such Limited Secured Acquisition Debt.

The 8.25% Notes are subordinated in right of payment to certain indebtedness and obligations of the Company, as described in the 8.25% Notes Indenture (the “Issuer Senior Debt”), including (i) any indebtedness of the Company (inclusive of any indebtedness of Enrichment Corp.) under a future credit facility up to $50 million with a maximum net borrowing of $40 million after taking into account any minimum cash balance (unless a higher amount is approved with the consent of the holders of a majority of the aggregate principal amount of the 8.25% Notes then outstanding), (ii) any revolving credit facility to finance inventory purchases and related working capital needs, and (iii) any indebtedness of the Company to Enrichment Corp. under the secured intercompany notes.

The 8.25% Notes are guaranteed on a subordinated and limited basis by, and secured by substantially all of the assets of, Enrichment Corp. The Enrichment Corp. guarantee is a secured obligation and ranks equally in right of payment with all existing and future unsubordinated indebtedness of Enrichment Corp. (other than Designated Senior Claims (as defined below) and Limited Secured Acquisition Debt) and senior in right of payment to all existing and future subordinated indebtedness of Enrichment Corp. and Limited Secured Acquisition Debt. The Enrichment Corp. guarantee is subordinated in right of payment to certain obligations of, and claims against, Enrichment Corp. described in the 8.25% Notes Indenture (collectively, the “Designated Senior Claims”), including obligations and claims:


•	under a future credit facility up to $50 million with a maximum net borrowing of $40 million after taking into account any minimum cash balance;


•	under any revolving credit facility to finance inventory purchases and related working capital needs;


•	held by or for the benefit of the Pension Benefit Guaranty Corporation (“PBGC”) pursuant to any settlement (including any required funding of pension plans); and


•	under surety bonds or similar obligations held by or on behalf of the U.S. government pursuant to regulatory requirements.

The liens securing the Enrichment Corp. guarantee of the PIK Toggle Notes and the 8.25% Notes are pari passu with each other, and are junior in priority with respect to the lien securing Limited Secured Acquisition Debt, which is limited to the assets acquired with such Limited Secured Acquisition Debt.

8% PIK Toggle Notes

Interest on the 8% PIK Toggle Notes is payable semi-annually in arrears on March 31 and September 30 based on a 360-day year consisting of twelve 30-day months. The principal amount is increased by any payment of interest in the form of PIK payments. The Company has the option to pay up to 5.5% per annum of interest due on the 8% PIK Toggle Notes in the form of PIK payments. For the semi-annual interest periods in 2017 and 2018, the Company elected to pay interest in the form of PIK payments at 5.5% per annum. Financing costs for the issuance of the 8% PIK Toggle Notes were deferred and are being amortized on a straight-line basis, which approximates the effective interest method, over the life of the 8% PIK Toggle Notes. The 8% PIK Toggle Notes mature on September 20, 2019. However, the maturity date may be extended to September 30, 2024, upon the satisfaction of certain funding conditions described in the applicable indenture.

The 8% PIK Toggle Notes mature on September 30, 2019. However, the maturity date can be extended to September 30, 2024, upon the satisfaction of certain funding conditions described in the Indenture relating to the funding, under binding agreements, of (i) the American Centrifuge project or (ii) the implementation and deployment of a National Security Train Program utilizing American Centrifuge technology.

The 8% PIK Toggle Notes rank equally in right of payment with all existing and future unsubordinated indebtedness of the Company (other than the Issuer Senior Debt) and are senior in right of payment to all existing and future subordinated indebtedness of the Company. The 8% PIK Toggle Notes are subordinated in right of payment to the Issuer Senior Debt.

The 8% PIK Toggle Notes are guaranteed and secured on a subordinated, conditional, and limited basis by Enrichment Corp. Enrichment Corp. will be released from its guarantee without the consent of the holders of the 8% PIK Toggle Notes upon the occurrence of certain termination events (other than with respect to an unconditional interest claim), including (i) the involuntary termination by the Pension Benefit Guaranty Corporation (“PBGC”) of any of the qualified pension plans of the Company or Enrichment Corp, (ii) the cessation of funding prior to completion of our ongoing American Centrifuge test programs or (iii) both a decision by the Company to abandon American Centrifuge technology and either (1) the efforts by the Company to commercialize another next generation enrichment technology funded at least in part by new capital provided or to be provided by Enrichment Corp. have been terminated or are no longer being pursued or (2) the attainment of capital necessary to commercialize another next generation enrichment technology with respect to which the issuer is involved which does not include new capital provided or to be provided by Enrichment Corp.

The Enrichment Corp. guarantee ranks equally in right of payment with all existing and future unsubordinated indebtedness of Enrichment Corp. (other than the Designated Senior Claims and Limited Secured Acquisition Debt) and senior in right of payment to all existing and future subordinated indebtedness of Enrichment Corp. and Limited Secured Acquisition Debt. The Enrichment Corp. guarantee is subordinated in right of payment to the Designated Senior Claims.

Fair Value Measurements

12 Months Ended

Dec. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE

Fair value is the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value of assets and liabilities, the following hierarchy is used in selecting inputs, with the highest priority given to Level 1, as these are the most transparent or reliable:


•	Level 1 – quoted prices for identical instruments in active markets.


•	Level 2 – quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets.


•	Level 3 – valuations derived using one or more significant inputs that are not observable.

Financial Instruments Recorded at Fair Value (in millions):



	December 31, 2018								December 31, 2017
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets:
Cash and cash equivalents	$	123.1	$	—	$	—	$	123.1	$	208.8	$	—	$	—	$	208.8
Deferred compensation asset (a)	1.4		—		—		1.4		1.4		—		—		1.4

Liabilities:
Deferred compensation obligation (a)	$	1.4	$	—	$	—	$	1.4	$	1.4	$	—	$	—	$	1.4


(a)	The deferred compensation obligation represents the balance of deferred compensation plus net investment earnings. The deferred compensation plan is funded through a rabbi trust. Trust funds are invested in mutual funds for which unit prices are quoted in active markets and are classified within Level 1 of the valuation hierarchy.

There were no transfers between Level 1, 2 or 3 during the periods presented.

Other Financial Instruments

As of December 31, 2018, and December 31, 2017, the balance sheet carrying amounts for Accounts Receivable, Accounts Payable and Accrued Liabilities (excluding the deferred compensation obligation described above), and Payables under SWU Purchase Agreements approximate fair value because of their short-term nature.

The carrying value and estimated fair value of long-term debt are as follows (in millions):



	December 31, 2018					December 31, 2017
	Carrying Value			Estimated Fair Value ^(a)		Carrying Value			Estimated Fair Value ^(a)
8.25% Notes	$	126.3	^(b)	$	57.9	$	132.4	^(b)	$	61.7
8% PIK Toggle Notes	26.7			21.8		31.3			25.1

^(a) Based on recent trading prices and bid/ask quotes as of or near the balance sheet date, which are considered Level 2 inputs based on the frequency of trading.


^(b)	The carrying value of the 8.25% Notes consists of the principal balance of $74.3 million and the sum of current and noncurrent interest payment obligations until maturity. Refer to Note 9, Debt.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Pension and Postretirement Health and Life Benefits

12 Months Ended

Dec. 31, 2018

Retirement Benefits, Description [Abstract]

Pension and Postretirement Health and Life Benefits

PENSION AND POSTRETIREMENT HEALTH AND LIFE BENEFITS

There are approximately 5,000 employees and retirees covered by qualified defined benefit pension plans providing retirement benefits based on compensation and years of service, and approximately 3,100 employees and retirees covered by postretirement health and life benefit plans. DOE retained the obligation for postretirement health and life benefits for workers who retired prior to July 28, 1998. Pursuant to non-qualified supplemental pension plans, Centrus provides certain executive officers additional retirement benefits in excess of qualified plan limits imposed by tax law based on a targeted benefit objective. Employees hired on or after September 1, 2008, who are not covered by a collective bargaining agreement that provides for participation do not participate in a qualified defined benefit pension plan or postretirement health and life benefit plans.

Changes in the projected benefit obligations and plan assets and the funded status of the plans follow:



	Defined Benefit Pension Plans						Postretirement Health and Life Benefit Plans
($ millions)	Year Ended December 31,						Year Ended December 31,
	2018			2017			2018			2017
Changes in Benefit Obligations:
Obligations at beginning of period	$	817.9		$	814.6		$	170.7		$	192.8
Actuarial (gains) losses, net	(50.8		)	32.8			(13.1		)	(24.8		)
Service costs	3.4			3.7			—			—
Interest costs	28.7			32.2			5.8			7.2
Benefits paid	(57.5		)	(59.3		)	(11.8		)	(14.5		)
Lump sum benefits paid	(4.8		)	(2.9		)	—			—
Plan change	—			—			—			10.0
Administrative expenses paid	(3.1		)	(3.2		)	—			—
Obligations at end of period	733.8			817.9			151.6			170.7
Changes in Plan Assets:
Fair value of plan assets at beginning of period	654.6			634.1			1.8			7.7
Actual return on plan assets	(40.2		)	84.4			—			0.1
Company contributions	14.5			1.5			10.0			8.5
Benefits paid	(57.5		)	(59.3		)	(11.8		)	(14.5		)
Lump sum benefits paid	(4.8		)	(2.9		)	—			—
Administrative expenses paid	(3.1		)	(3.2		)	—			—
Fair value of plan assets at end of period	563.5			654.6			—			1.8
Unfunded status at end of period	$	(170.3	)	$	(163.3	)	$	(151.6	)	$	(168.9	)

Amounts recognized in assets and liabilities:
Current liabilities	$	(1.4	)	$	(1.7	)	(15.4		)	(14.7		)
Noncurrent liabilities	(168.9		)	(161.6		)	(136.2		)	(154.2		)
	$	(170.3	)	$	(163.3	)	$	(151.6	)	$	(168.9	)
Amounts in accumulated other comprehensive income (loss), pre-tax:
Prior service cost (credit)	$	—		$	—		$	(2.4	)	$	(2.5	)

Discount rate used to determine benefit obligations at end of period:	4.3		%	3.7		%	4.3		%	3.6		%

The current liabilities reflect expected contributions for benefit payments for the non-qualified plans and the postretirement health and life benefit plans in the following year.

The discount rates above, rounded to the nearest 0.1%, are the estimated rates at which the benefit obligations could be effectively settled on the measurement date and are based on yields of high quality fixed income investments whose cash flows match the timing and amount of expected benefit payments of the plans.

Plan assets and benefit obligations are remeasured each year as of the balance sheet date resulting in differences between actual and projected results for the year. These actuarial gains and losses are recognized in the statement of operations in the fourth quarter. In addition, an interim remeasurement and recognition of gains or losses may be required for a plan during the year when lump sum payments exceed, or are expected to exceed, the sum of the service cost and interest cost components of the annual net periodic benefit cost for that plan for the current year. There were no interim remeasurements in 2018 and 2017.

The defined benefit pension plans currently allow for a lump sum payment option to (a) active employees who are terminated as a result of Company reductions in force and (b) periodically to terminated vested participants. The lump sum payment option was most recently extended through September 2019 to those terminated vested participants who have not yet begun receiving their benefits and have been terminated as a result of a reduction in force by the Company, or due to voluntary termination or involuntary termination, other than involuntary termination as a termination for cause.

Projected benefit obligations are based on actuarial assumptions including possible future increases in compensation. Accumulated benefit obligations are based on actuarial assumptions but do not include possible future increases in compensation. Effective August 2013, accrued benefits under the defined benefit pension plans are fixed and no longer increase to reflect changes in compensation or company service. Therefore, the accumulated benefit obligation equaled the projected benefit obligation of $733.8 million and $817.9 million as of December 31, 2018 and 2017, respectively. As of December 31, 2018 and 2017, none of Centrus’ plans had fair value of plan assets in excess of accumulated benefit obligations.

Components of Net Periodic Benefit Costs and Other Amounts Recognized in Other Comprehensive Income (Loss)

The Company reports service costs for its defined benefit pension plans and its postretirement health and life benefit plans in Cost of Sales and Selling, General and Administrative Expenses. The remaining components of net periodic benefit credits (costs) are reported as Nonoperating Components of Net Periodic Benefit Expense (Income).



	Defined Benefit Pension Plans						Postretirement Health and Life Benefit Plans
(in millions)	Year Ended December 31,						Year Ended December 31,
	2018			2017			2018			2017
Net Periodic Benefit (Credits) Costs
Service costs	$	3.4		$	3.7		$	—		$	—
Interest costs	28.7			32.2			5.8			7.2
Expected return on plan assets (gains)	(41.0		)	(40.7		)	—			—
Amortization of prior service costs (credits), net	—			—			(0.2		)	(0.1		)
Actuarial (gains) losses, net	30.4			(10.9		)	(13.1		)	(24.9		)
Loss on plan changes resulting from legal settlement	—			—			—			10.0
Net periodic benefit (credits) costs	$	21.5		$	(15.7	)	$	(7.5	)	$	(7.8	)



Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Amortization of prior service (costs) credits, net	$	—	$	—		$	0.2		$	0.1
Total loss recognized in other comprehensive income (loss), pre-tax	$	—	$	—		$	0.2		$	0.1
Total recognized in net periodic benefit costs (income) and other comprehensive income (loss), pre-tax	$	21.5	$	(15.7	)	$	(7.3	)	$	(7.7	)

Net periodic benefit costs include service and interest costs of providing pension benefits that are accrued over the years employees render service. Prior service costs or credits are amortized over the employees’ average remaining years of service from age 40 until the date of full benefit eligibility or the average expected future lifetime of all plan participants, as applicable. Participants in the postretirement health and life benefit plans are generally eligible for benefits at retirement after age 50 with 10 years of continuous credited service at the time of retirement.

Effective January 1, 2014, or for certain plan participants formerly represented by a collective bargaining unit, January 1, 2015, plan participants age 65 or older (“post-65”) have access to a range of medical plan choices with varying costs and benefits through a Medicare Exchange implemented by the Company. The Company provides an annual stipend for each of the post-65 retirees and post-65 spouses who enroll in the coverage through the exchange. Depending on the level of benefits elected by the participant, the participant may be required to make contributions in excess of the stipend amount.

The transition to the post-65 Medicare Exchange was reflected as a plan amendment that reduced plan obligations by $6.8 million as of December 31, 2014. This reduction in obligation was recognized in other comprehensive income in 2014 as a prior service credit. The prior service credit is being amortized into net periodic benefit cost as a credit over time. The post-65 Medicare Exchange stipend amount was increased for 2017. This increase in obligation of $3.6 million as of December 31, 2016, was recognized in other comprehensive income in 2016 as a prior service cost and is being amortized into net periodic benefit cost over time. The post-65 Medicare Exchange stipend amount was increased in 2018, as specified in a settlement agreement with the former collective bargaining unit. The settlement agreement also specifies the addition of catastrophic drug coverage effective January 1, 2019. The benefit enhancement for 2019 has been applied to all post-65 participants regardless of past representation by the collective bargaining agreement. The increase in obligation of $10.0 million as a result of the settlement agreement was recognized in net periodic benefit costs in 2017 as a plan change resulting from a legal settlement and is reported in Nonoperating Components of Net Periodic Benefit Expense (Income).

Assumptions Used to Determine Net Periodic Benefit Costs



	Defined Benefit Pension Plans		Postretirement Health and Life Benefit Plans
	Year Ended December 31,		Year Ended December 31,
	2018	2017	2018	2017
Discount rate	4.3%	3.7%	4.3%	3.6%
Expected return on plan assets	6.8%	6.8%	—	—

The expected return on plan assets is based on the weighted average of long-term return expectations for the composition of the plans’ equity and debt securities. Expected returns on equity securities are based on historical long-term returns of equity markets. Expected returns on debt securities are based on the current interest rate environment.

Healthcare cost trend rates used to measure postretirement health benefit obligations follow:



	December 31,
	2018	2017
Healthcare cost trend rate for the following year	6.0%	6.5%
Long-term rate that the healthcare cost trend rate gradually declines to	5%	5%
Year that the healthcare cost trend rate is expected to reach the long-term rate	2021	2021

A one-percentage-point change in the assumed healthcare cost trend rates would have an effect on the postretirement health benefit obligation and costs as follows:



(in millions)	One-Percentage Point
	Increase		Decrease
Postretirement health benefit obligation	$	2.9	$	(2.7	)
Net periodic benefit costs (service and interest cost components only)	$	0.1	$	(0.1	)

Benefit Plan Assets

Independent advisors manage investment assets of Centrus’ defined benefit pension plans and postretirement health and life benefit plans. Centrus has the fiduciary responsibility for reviewing performance of the various investment advisors. The investment policy of the plans is to maximize portfolio returns within reasonable and prudent levels of risk in order to meet projected liabilities and maintain sufficient cash to make timely payments of all participant benefits. Risk is reduced by diversifying plan assets and following a strategic asset allocation approach. Asset classes and target weights are adjusted periodically to optimize the long-term portfolio risk/return tradeoff, to provide liquidity for benefit payments, and to align portfolio risk with the underlying obligations. The investment policy of the plans prohibits the use of leverage, direct investments in tangible assets, or any investment prohibited by applicable laws or regulations.

The allocation of plan assets between equity and debt securities and the target allocation range by asset category for the defined benefit pension plans follows:



	December 31,
	2018		2017		2019 Target
Equity securities	48	%	49	%	40	-	60%
Debt securities	49	%	49	%	40	-	60%
Cash	3	%	2	%	0	-	5%
	100	%	100	%

Prefunding for the postretirement health and life benefit plans was discontinued in 2012 and the remaining assets were invested in short-term bond funds as of December 31, 2017, and were expended in early 2018. Benefit costs of the postretirement health and life benefit plans are primarily funded as costs are incurred.

Plan assets are measured at fair value. Following are the plan investments as of December 31, 2018 and 2017, categorized by the fair value hierarchy levels described in Note 10, Fair Value Measurements:



	Defined Benefit Pension Plans
(in millions)	Level 1				Level 2				Level 3				Total
	2018		2017		2018		2017		2018		2017		2018		2017
U.S. government securities	$	—	$	—	$	34.6	$	34.6	$	—	$	—	$	34.6	$	34.6
Corporate debt	—		—		104.7		119.7		—		—		104.7		119.7
Municipal bonds and non-U.S. government securities	—		—		2.0		3.5		—		—		2.0		3.5
Mortgage and asset backed securities	—		—		4.2		0.3		—		—		4.2		0.3
Fair value of investments by hierarchy level	$	—	$	—	$	145.5	$	158.1	$	—	$	—	$	145.5	$	158.1
Investments measured at NAV (a)													416.1		494.7
Accrued interest receivable													1.8		1.9
Unsettled transactions													0.1		(0.1		)
Plan assets													$	563.5	$	654.6



	Postretirement Health and Life Benefit Plans
(in millions)	Level 1				Level 2				Level 3				Total
	2018		2017		2018		2017		2018		2017		2018		2017
Money market funds	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Bond mutual funds	—		1.8		—		—		—		—		—		1.8
Fair value of investments by hierarchy level	$	—	$	1.8	$	—	$	—	$	—	$	—	$	—	$	1.8

(a) Equity, bond and money market investments held in collective trusts are valued based on the net asset value (“NAV”) provided by the administrator of the funds. The NAV for each fund is based on the underlying assets owned by the fund, less any expenses accrued against the fund, divided by the number of fund shares outstanding. While the underlying investments are traded on an exchange, the funds are not. Fair values for the collective trust investments are measured using the NAVs as a practical expedient and are not categorized in the fair value hierarchy.

Level 1 assets consist of mutual funds and money market funds having a publicly available NAV.

Level 2 assets include investments in U.S. government agency securities, corporate and municipal debt that are valued based on estimated prices using observable, market-based inputs.

Benefit Plan Cash Flows

Centrus expects to contribute $9.4 million to the qualified defined benefit pension plans, $1.4 million to the non-qualified defined benefit pension plans and $15.3 million to the postretirement health and life benefit plans in 2019. There is no required contribution for the postretirement health and life benefit plans under Employee Retirement Income Security Act (“ERISA”).

Estimated future benefit plan payments follow (in millions):



	Defined Benefit Pension Plans		Postretirement Health and Life Benefit Plans
2019	$	57.9	$	15.3
2020	56.0		13.9
2021	54.8		13.2
2022	53.6		12.6
2023	52.4		12.1
2024 to 2028	245.1		49.3

Other Plans

Centrus sponsors a 401(k) defined contribution plan for employees. Employee contributions are matched at established rates. Amounts contributed are invested in a range of investment options available to participants and the funds are administered by an independent trustee. Matching cash contributions by the Company amounted to $1.8 million in 2018 and $2.3 million in 2017.

Under the Executive Deferred Compensation Plan, qualified employees may defer compensation on a tax-deferred basis subject to plan limitations. Any matching contributions under the Company’s 401(k) plan that are foregone due to annual compensation limitations of the Internal Revenue Code are eligible to be received from the Company under the Executive Deferred Compensation Plan, provided that the employee deferred the maximum allowable pre-tax contribution in the 401(k) plan. Centrus matching contributions amounted to less than $0.1 million in 2018 and 2017.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2018

Share-based Compensation [Abstract]

Stock-Based Compensation

STOCK-BASED COMPENSATION

The Company’s 2014 Equity Incentive Plan authorizes the issuance of stock options, stock appreciation rights, restricted stock units, restricted stock, performance awards, dividend equivalent rights and other stock-based awards, as well as cash-based awards to employees, officers, directors and other individuals providing services to the Company or its affiliates. The plan authorizes the issuance of up to 1,200,000 shares of Class A Common Stock. As of December 31, 2018, there were approximately 596,000 shares available for future awards, including approximately 120,000 shares associated with awards that were cancelled or forfeited without being exercised.

A summary of stock-based compensation costs follows (in millions):



	Year Ended December 31,
	2018		2017

Total stock-based compensation costs:
Restricted stock units	$	0.1	$	0.1
Stock options	0.3		0.4
Expense included in selling, general and administrative expense	$	0.4	$	0.5

Total recognized tax benefit	$	—	$	—

The total recognized tax benefit is reported at the federal statutory rate net of the tax valuation allowance.

Stock-based compensation cost is measured at the grant date, based on the fair value of the award, and is recognized on a straight-line basis over the requisite service period. As of December 31, 2018, there was $0.1 million of unrecognized compensation cost, adjusted for actual forfeitures, related to non-vested stock-based payments granted, of which $0.1 million relates to stock options and less than $0.1 million relates to restricted stock units. That cost is expected to be recognized over a weighted-average period of 3 months. There were no stock options granted, exercised or forfeited during the years ended December 31, 2018 and 2017.

Restricted Stock Units

Non-employee, independent directors are granted restricted stock units as part of their compensation for serving on the Board of Directors. Settlement of these restricted stock units is made in shares of Class A Common Stock only upon the director’s retirement or other end of service. The restricted stock units generally vest over one year; however, vesting is accelerated upon (1) the director attaining eligibility for retirement, (2) termination of the director’s service by reason of death or disability, or (3) a change in control. As of December 31, 2018, approximately 141,000 shares of restricted stock units could potentially be converted to Class A Common Stock once vested and settled.

The fair value of restricted stock units is determined based on the closing price of Class A Common Stock on the grant date. Compensation cost for restricted stock units is amortized to expense on a straight-line basis over the vesting period.

Stock Options

The intrinsic value of an option, if any, represents the excess of the fair value of the common stock over the exercise price. The fair value of stock option awards is estimated using the Black-Scholes option pricing model, which includes a number of assumptions including Centrus’ estimates of stock price volatility, employee stock option exercise behaviors, future dividend payments, and risk-free interest rates.

The expected term of options granted is the estimated period of time from the beginning of the vesting period to the date of expected exercise or other settlement, based on historical exercises and post-vesting terminations. Centrus has estimated the expected term using the simplified method described in SEC Staff Accounting Bulletin No. 107/110, Share-Based Payment, due to the lack of historical exercise and post-vesting termination information available for the Company since its reorganization. Future stock price volatility is estimated based on the Company’s historical volatility. The risk-free interest rate for the expected option term is based on the U.S. Treasury yield curve in effect at the time of grant. No cash dividends are expected in the foreseeable future and, therefore, an expected dividend yield of zero is used in the option valuation model. For reporting periods prior to January 1, 2017, the Company used historical data to estimate pre-vesting option forfeitures at the time of grant and revised those estimates in subsequent periods if actual forfeitures differed from the estimates. Effective January 1, 2017, the Company recognizes forfeitures as they occur. Compensation expense is recognized for stock option awards that are expected to vest. There were no option grants in the years ended December 31, 2018 and 2017.

Stock options vest and become exercisable in equal annual installments over a three or four year period and expire ten years from the date of grant. A summary of stock option activity follows:



	Stock Options (thousands)	Weighted Average Exercise Price	Weighted Average Remaining Contractual Life in Years	Aggregate Intrinsic Value (millions)

Outstanding at December 31, 2017	425	$4.14	7.3	$0.1
Outstanding at December 31, 2018	425	$4.14	6.3	$—
Exercisable at December 31, 2018	345	$4.11	6.3	$—

Stock options outstanding and options exercisable at December 31, 2018, follow:



Stock Exercise Price	Options Outstanding (thousands)	Remaining Contractual Life in Years	Options Exercisable (thousands)

$5.62	22	5.9	22
$4.37	300	6.2	225
$3.90	23	6.6	23
$3.93	15	6.6	15
$2.71	50	6.8	50
$2.68	15	7.4	10

Income Taxes

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

INCOME TAXES

Benefit

The benefit from income taxes from continuing operations is as follows (in millions):



	Year Ended December 31,
	2018		2017
Current:
Federal	$	—	$	—
State and local	—		(0.1		)
Foreign	—		—
	—		(0.1		)
Deferred:
Federal	—		—
State and local	—		—
Foreign	—		—
	—		—
	$	—	$	(0.1	)

Deferred Taxes

Future tax consequences of temporary differences between the carrying amounts for financial reporting purposes and the Company’s estimate of the tax bases of its assets and liabilities result in deferred tax assets and liabilities, as follows (in millions):



	December 31,
	2018			2017
Deferred tax assets:
Employee benefits costs	$	73.6		$	79.9
Inventory	11.1			2.4
Property, plant and equipment	185.9			187.0
Net operating loss and credit carryforwards	187.1			166.9
Accrued expenses	0.9			0.9
Long-term debt and financing costs	15.3			17.3
Other	0.2			5.5
	474.1			459.9
Valuation allowance	(456.6		)	(440.7		)
Deferred tax assets, net of valuation allowance	$	17.5		$	19.2

Deferred tax liabilities:
Intangible assets	$	16.0		$	17.7
Prepaid expenses	1.5			1.5
Deferred tax liabilities	$	17.5		$	19.2
	$	—		$	—

The valuation allowance reduces the net deferred tax assets to their net realizable value. There is a full valuation allowance against net deferred taxes due to annual operating losses since 2011 and substantial uncertainty to generate future taxable income that would lead to realization of the net deferred tax assets. When a change in the tax rate or tax law has an impact on deferred taxes, we apply the change based on the years in which the deferred taxes are expected to reverse. The Company records the impact of the change in its consolidated financial statements in the period of enactment. For the year ended December 31, 2017, the Company recorded a decrease in net deferred tax assets before valuation allowance which resulted primarily from the remeasurement at 21% in accordance with the Tax Act. The ultimate realization of the net deferred tax assets is dependent upon generating sufficient taxable income in future years when deferred tax assets are recoverable or are expected to reverse.

The Company has federal net operating losses of $791.3 million generated through December 31, 2017 that currently expire through 2037. In addition, the Company has federal net operating losses and business interest expense carry forwards of $89.2 million and $10.1 million, respectively, generated after December 31, 2017, that do not expire. The Company has concluded that a full valuation allowance is needed for all federal net operating losses. In 2014, the federal net operating losses as well as other tax attributes consisting primarily of tax basis in property of approximately $15.3 million were reduced as a result of Centrus’ cancellation of debt income of approximately $340 million as prescribed by Internal Revenue Code Section 108. Centrus also has state net operating losses of $0.3 million that currently expire through 2038. The deferred tax assets for state net operating losses and state unrealized built-in loss deductions have been reduced as a result of Centrus’ tax ownership change and cancellation of debt income in 2014.

Centrus experienced an ownership change as defined under Internal Revenue Code Section 382 on September 30, 2014 when it emerged from bankruptcy. Generally, after an ownership change, the use of federal and state net operating loss carryforwards and tax credits generated prior to the ownership change are subject to an annual limitation. However, there is an exception available to qualifying corporations that eliminates the annual limitation. Centrus can utilize this exception for federal purposes, but not for state purposes. The pre-apportioned annual state limitation is $2.9 million. Centrus also had an unrealized built-in loss as of the ownership change date. To the extent this built-in loss is recognized during the five-year post-ownership change period through certain depreciation and loss deductions, the same annual limitation for loss and tax credit carryforwards also applies generally to a built-in loss when it is recognized, unless the exception applies. Centrus can utilize the same exception for federal purposes when the built-in loss is recognized, but not for state purposes. To the extent the built-in loss is recognized during the five-year post-ownership change period, the same pre-apportioned state limitation will apply so that the combination of loss carryforwards and recognized built-in losses cannot exceed $2.9 million annually.

Effective Tax Rate

A reconciliation of income taxes calculated based on the federal statutory income tax rate and the effective tax rate follows:



	Year Ended December 31,
	2018		2017
Federal statutory tax rate	21	%	35	%
Valuation allowance against net deferred tax assets	(15	)	(2,156	)
State rate changes	(6	)	—
Executive compensation	(1	)	—
State income tax expense, net of federal benefit	1		1
Tax Cuts and Jobs Act of 2017	—		2,382
Gain on early extinguishment of debt	—		(268	)
Interest expense	—		4
Other non-deductible expenses	—		1
Effective tax rate	—	%	(1	)%

The Tax Act enacted on December 22, 2017 reduced the U.S. federal corporate income tax rate from 35% to 21%, effective January 1, 2018. The SEC staff issued Staff Accounting Bulletin 118 (“SAB 118”), which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under Accounting Standards Codification 740, Income Taxes (“ASC 740”). In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that a company’s accounting for certain income tax effects of the Tax Act is incomplete, but it can determine a reasonable estimate, it must record a provisional estimate in the financial statements. The Company has completed its accounting for the tax effects of the Tax Act, and based on the Company’s net operating loss carryovers and full valuation allowance, there is no impact to its consolidated financial statements.

As a result of the reduction of the federal corporate income tax rate, the net deferred tax assets have been remeasured as of December 31, 2017. Primarily as a result of the remeasurement, the effective tax rate for the year ended December 31, 2017 includes a decrease to the net deferred tax assets of $288.9 million, or an increase to the effective tax rate of 2,382%. The effective tax rate also includes a decrease to the valuation allowance against net deferred tax assets of $261.5 million, or a change to the effective tax rate of (2,156)%, and an adjustment to the gain on early extinguishment of debt of $32.5 million or a change to the effective tax rate of (268)%. The Tax Act did not affect the income tax provision for the year ended December 31, 2017.

The effective tax rate for the year ended December 31, 2018 includes an increase to the valuation allowance against net deferred tax assets of $15.9 million, or a change to the effective tax rate of (15)%, and a $6 million decrease to the state deferred tax assets resulting from state rate changes, or a change to the effective tax rate of (6)%.

Uncertain Tax Positions

Accounting standards require that a tax position meet a minimum recognition threshold in order for the related tax benefit to be recognized in the financial statements. The liability for unrecognized tax benefits, included in Other Long-Term Liabilities, was $0.2 million as of December 31, 2018 and $0.3 million as of December 31, 2017. If recognized, these tax benefits would impact the effective tax rate. As a result of changes to unrecognized tax benefits, the income tax provision (state tax, net of federal benefit) decreased $0.1 million during the years ended December 31, 2018 and December 31, 2017. The liability for unrecognized tax benefits in the table below relates to unrecognized state income tax benefits. Centrus believes that the liability for unrecognized tax benefits will not change significantly in the next 12 months.

A reconciliation of the beginning and ending amount of unrecognized tax benefits follows (in millions):



	Year Ended December 31,
	2018			2017
Balance at beginning of the period	$	0.3		$	0.4
Additions to tax positions of current period	—			0.1
Reductions to tax positions of prior years	(0.1		)	(0.2		)
Balance at end of the period	$	0.2		$	0.3

Centrus and its subsidiaries file income tax returns with the U.S. government and various states and foreign jurisdictions. As of December 31, 2018, the federal and Maryland statutes of limitation are closed with respect to all tax years through 2014, and the Kentucky statute of limitations is closed with respect to all tax years through 2013.

Centrus recognizes accrued interest related to uncertain tax positions as a component of interest expense. Reversals of previously accrued interest for income taxes is typically offset against interest expense, but if the amount is significant, it is reclassified to interest income in the consolidated statement of operations. Centrus recognizes the increase or decrease of accrued penalties for income taxes as a component of selling, general and administrative expense in the consolidated statement of operations.

The impact of accrued interest and penalties for income taxes in the consolidated statement of operations was a reduction to expenses of less than $0.1 million for the years ended December 31, 2018 and 2017. Accrued interest and penalties for income taxes, included as a component of Other Long-Term Liabilities, totaled less than $0.1 million as of December 31, 2018 and 2017.

Net Income Per Share

12 Months Ended

Dec. 31, 2018

Earnings Per Share [Abstract]

Net Income (Loss) Per Share

NET INCOME (LOSS) PER COMMON SHARE

Basic net income (loss) per common share is calculated by dividing income (loss) allocable to common stockholders by the weighted average number of shares of common stock outstanding during the period. In calculating diluted net income (loss) per common share, the number of shares is increased by the weighted average number of potential shares related to stock compensation awards. No dilutive effect is recognized in a period in which a net loss has occurred. The weighted average number of common and common equivalent shares used in the calculation of basic and diluted income (loss) per common share are as follows:



	Year ended December 31,
	2018			2017
Numerator (in millions):
Net income (loss)	$	(104.1	)	$	12.2
Preferred stock dividends - undeclared and cumulative	7.8			6.9
Net income (loss) allocable to common stockholders	$	(111.9	)	$	5.3

Denominator (in thousands):
Average common shares outstanding - basic	9,151			9,081
Potentially dilutive shares related to stock options and restricted stock units^(a)	—			—
Average common shares outstanding - diluted	9,151			9,081

Net income (loss) per common share (in dollars) - basic and diluted:	$	(12.23	)	$	0.58

(a) Common stock equivalents excluded from the diluted calculation as a result of a net loss in the period (in thousands)	23			—

Options outstanding and considered anti-dilutive as their exercise price exceeded the average share market price (in thousands)	360			200

Stockholders' Equity

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Attributable to Parent [Abstract]

Stockholders' Equity Note Disclosure [Text Block]

STOCKHOLDERS’ EQUITY

Common Stock

The Company’s certificate of incorporation authorizes 20,000,000 shares of preferred stock, par value $1.00 per share, 70,000,000 shares of Class A common stock, $0.10 par value per share (the “Class A Common Stock”) and 30,000,000 shares of Class B common stock, $0.10 par value per share (the “Class B Common Stock,” and together with the Class A Common Stock, the “Common Stock”). The Company has issued 9,437,389 shares of Common Stock, consisting of 8,031,307 shares of Class A Common Stock and 1,406,082 shares of Class B Common Stock.

On December 6, 2018, Centrus issued 398,638 shares of Class A Common Stock with a $0.10 par value, as part of the securities exchange described in Note 9, Debt. The Class A Common Stock is recorded on the consolidated balance sheet at fair value less transaction costs, or $0.8 million, as of December 31, 2018.

A total of 38,751 shares of Class A Common Stock were issued in settlement of vested restricted stock units to three former members of the Board of Directors following the end of their service on May 31, 2017. Shares of Class B Common Stock that are sold in the market are automatically converted to shares of Class A Common Stock. In the twelve months ended December 31, 2017, a total of 30,318 shares of Class B Common Stock were sold in the market and converted to shares of Class A Common Stock as of December 31, 2017.

The Company has reserved 1,200,000 shares of Class A Common Stock under its management incentive plan, of which approximately 596,000 shares are available for future awards as of December 31, 2018. Refer to Note 12, Stock-Based Compensation, for additional information.

The Class A Common Stock trades under the symbol “LEU” on the NYSE American trading platform.

The Class B Common Stock was issued to Toshiba America Nuclear Energy Corporation (“Toshiba”) and Babcock & Wilcox Investment Company (“B&W”) and has the same rights, powers, preferences and restrictions and ranks equally in all matters with the Class A Common Stock, except voting. Holders of Class B Common Stock are entitled to elect, in the aggregate, two members of the Board of Directors of the Company, subject to certain holding requirements.

Series B Preferred Stock

On February 14, 2017, Centrus issued 104,574 shares of Series B Preferred Stock as part of the securities exchange described in Note 9, Debt. The issuance of the Series B Preferred Stock was a non-cash financing transaction. The Series B Preferred Stock has a par value of $1.00 per share and a liquidation preference of $1,000 per share (the “Liquidation Preference”). The Series B Preferred Stock is recorded on the consolidated balance sheet at fair value less transaction costs, or $4.6 million, as of December 31, 2018, and December 31, 2017.

Holders of the Series B Preferred Stock are entitled to cumulative dividends of 7.5% per annum of the Liquidation Preference. Centrus is obligated to pay cash dividends on the Series B Preferred Stock in an amount equal to the Liquidation Preference to the extent that dividends are declared by the Board and:


(a)	its pension plans and Enrichment Corp.’s pension plans are at least 90% funded on a variable rate premium calculation in the current plan year;


(b)	its net income calculated in accordance with GAAP (excluding the effect of pension remeasurement) for the immediately preceding fiscal quarter exceeds $7.5 million;


(c)	its free cash flow (defined as the sum of cash provided by (used in) operating activities and cash provided by (used in) investing activities) for the immediately preceding four fiscal quarters exceeds $35 million;


(d)	the balance of cash and cash equivalents calculated in accordance with GAAP on the last day of the immediately preceding quarter would exceed $150 million after pro forma application of the dividend payment; and


(e)	dividends may be legally paid under Delaware law.

Centrus has not met these criteria for the periods from issuance through December 31, 2018, and has not declared, accrued or paid dividends on the Series B Preferred Stock as of December 31, 2018. Dividends on the Series B Preferred Stock are cumulative to the extent not paid at any quarter-end, whether or not declared and whether or not there are assets of the Company legally available for the payment of such dividends in whole or in part. As of December 31, 2018, the Series B Preferred Stock has an aggregate liquidation preference of $119.3 million including accumulated dividends of $14.7 million. As of December 31, 2017, the Series B Preferred Stock had an aggregate liquidation preference of $111.5 million, including accumulated dividends of $6.9 million.

Outstanding shares of the Series B Senior Preferred Stock are redeemable at the Company’s option, in whole or in part, for an amount of cash equal to the Liquidation Preference, plus an amount equal to the accrued and unpaid dividends, if any, whether or not declared, through date of redemption.

Rights Agreement

On April 6, 2016 (the “Effective Date”), the Company’s Board of Directors (the “Board”) adopted a Section 382 Rights Agreement (the “Rights Agreement”). The Board adopted the Rights Agreement in an effort to protect shareholder value by, among other things, attempting to protect against a possible limitation on the Company’s ability to use its net operating loss carryforwards and other tax benefits, which may be used to reduce potential future income tax obligations.

In connection with the adoption of the Rights Agreement, the Board declared a dividend of one preferred-share-purchase-right for each share of the Company’s Class A Common Stock and Class B Common Stock outstanding as of the Effective Date. The rights initially trade together with the common stock and are not exercisable. In the absence of further action by the Board, the rights would generally become exercisable and allow a holder to acquire shares of a new series of the Company’s preferred stock if any person or group acquires 4.99% or more of the outstanding shares of the Company’s common stock, or if a person or group that already owns 4.99% or more of the Company’s Class A Common Stock acquires additional shares representing 0.5% or more of the outstanding shares of the Company’s Class A Common Stock. The rights beneficially owned by the acquirer would become null and void, resulting in significant dilution in the ownership interest of such acquirer.

The Board may exempt any acquisition of the Company’s common stock from the provisions of the Rights Agreement if it determines that doing so would not jeopardize or endanger the Company’s use of its tax assets or is otherwise in the best interests of the Company. The Board also has the ability to amend or terminate the Rights Agreement prior to a triggering event.

Effective on February 14, 2017, in connection with the settlement and completion of the exchange offer and consent solicitation, the Company amended the Rights Agreement solely to exclude acquisitions of the Series B Preferred Stock issued as part of the exchange offer and consent solicitation from the definition of “Common Shares.”

The Company’s stockholders approved the Rights Agreement at the 2017 annual meeting of stockholders on May 31, 2017. Unless earlier terminated or extended in accordance with the Rights Agreement, the rights issued under the Rights Agreement expire on April 5, 2019.

Shares Outstanding

Changes in the number of shares outstanding are as follows:



	Preferred Stock, Series B	Common Stock, Class A	Common Stock, Class B

Balance at December 31, 2016	—	7,563,600	1,436,400
Issuance of Preferred Stock	104,574	—	—
Issuance of Class A Common Stock	—	38,751	—
Conversion of Common Stock from Class B to Class A	—	30,318	(30,318	)
Balance at December 31, 2017	104,574	7,632,669	1,406,082

Issuance of Class A Common Stock	—	398,638	—
Balance at December 31, 2018	104,574	8,031,307	1,406,082

Commitments and Contingencies

12 Months Ended

Dec. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

COMMITMENTS AND CONTINGENCIES

Commitments under SWU Purchase Agreements

TENEX

A major supplier of SWU to the Company is the Russian government entity Joint Stock Company “TENEX” (“TENEX”). Under a 2011 agreement with TENEX, as amended, (the “Russian Supply Agreement”), the Company purchases SWU contained in LEU received from TENEX, and the Company delivers natural uranium to TENEX for the LEU’s uranium component. The LEU that the Company obtains from TENEX under the agreement is subject to quotas and other restrictions applicable to commercial Russian LEU.

The Russian Supply Agreement was originally signed with commitments through 2022 but was modified in 2015 to give the Company the right to reschedule certain quantities of SWU of the original commitments into the period 2023 and beyond, in return for the purchase of additional SWU in those years. If the Company exercises this right to reschedule in full during the remaining years of the contract’s original term, the Company will have a rescheduled post-2022 purchase commitment through 2028.

The Russian Supply Agreement provides that the Company must pay for all SWU in its minimum purchase obligation each year, even if it fails to submit orders for such SWU. The Company would then have the right to take the unordered SWU in the following year. Pricing terms for SWU under the Russian Supply Agreement are based on a combination of market-related price points and other factors. This formula is subject to an adjustment that the Company anticipates will reduce the unit costs of SWU under this contract for the duration of the contract.

Orano

On April 27, 2018, the Company entered into an agreement (the “Orano Supply Agreement”) with Orano Cycle (formerly, AREVA NC) (“Orano”) for the long-term supply to the Company of SWU contained in LEU, nominally commencing in 2023. Under the Agreement, the Company purchases SWU contained in LEU received from Orano, and the Company delivers natural uranium to Orano for the natural uranium feed material component of LEU. The Company may elect to begin to accept deliveries as early as 2021 or to defer the commencement of purchases until 2024 and has the option to extend the six-year purchase period for an additional two years. The Orano Supply Agreement provides significant flexibility to adjust purchase volumes, subject to annual minimums and maximums in fixed amounts that vary year by year. The pricing for the SWU purchased by the Company is determined by a formula that uses a combination of market-related price points and other factors, and is subject to certain floors and ceilings. Prices are payable in a combination of U.S. dollars and euros.

Nuclear Fuel Industries, Ltd.

On August 28, 2018, Enrichment Corp. entered into an agreement with Nuclear Fuel Industries, Ltd. (“NFI”) pursuant to which Enrichment Corp. would make a one-time purchase of SWU and uranium from NFI for $7.1 million. In March 2019, Enrichment Corp. completed the purchase from NFI. Toshiba America Nuclear Energy Corporation (“TANE”) holds 718,200 shares (51%) of the Company’s Class B common stock and certain of the Company’s 8.25% senior notes due 2027. Each of NFI and TANE are wholly-owned, indirect subsidiaries of Toshiba Corporation.

Milestones Under the 2002 DOE-USEC Agreement

The Company and DOE signed an agreement dated June 17, 2002, as amended (the “2002 DOE-USEC Agreement”), pursuant to which the parties made long-term commitments directed at resolving issues related to the stability and security of the domestic uranium enrichment industry. DOE consented to the assumption by Centrus of the 2002 DOE-USEC Agreement and other agreements between the Company and DOE subject to an express reservation of all rights, remedies and defenses by DOE and Centrus under those agreements as part of the Company’s Chapter 11 bankruptcy process. The 2002 DOE-USEC Agreement requires Centrus to develop, demonstrate and deploy advanced enrichment technology in accordance with milestones and provides for remedies in the event of a failure to meet a milestone under certain circumstances.

DOE has specific remedies under the 2002 DOE-USEC Agreement if Centrus fails to meet a milestone that would adversely impact its ability to begin commercial operations of the American Centrifuge Plant on schedule, and such delay was within Centrus’ control or was due to its fault or negligence or if Centrus abandons or constructively abandons the commercial deployment of an advanced enrichment technology. These remedies include terminating the 2002 DOE-USEC Agreement, revoking Centrus’ access to DOE’s centrifuge technology that is required for the success of the American Centrifuge project, requiring Centrus to transfer certain rights in the American Centrifuge technology and facilities to DOE, and requiring Centrus to reimburse DOE for certain costs associated with the American Centrifuge project.

The 2002 DOE-USEC Agreement provides that if a delaying event beyond the control and without the fault or negligence of Centrus occurs that could affect Centrus’ ability to meet an American Centrifuge Plant milestone, DOE and Centrus will jointly meet to discuss in good faith possible adjustments to the milestones as appropriate to accommodate the delaying event. The Company notified DOE that it had not met the June 2014 milestone within the time period provided due to events beyond its control and without the fault or negligence of the Company. The assumption of the 2002 DOE-USEC Agreement provided for under the Plan of Reorganization did not affect the ability of either party to assert all rights, remedies and defenses under the agreement and all such rights, remedies and defenses are specifically preserved and all-time limits tolled expressly including all rights, remedies and defenses and time limits relating to any missed milestones. DOE and Centrus have agreed that all rights, remedies and defenses of the parties with respect to any missed milestones since March 5, 2014, including the June 2014 and November 2014 milestones, and all other matters under the 2002 DOE-USEC Agreement continue to be preserved, and that the time limits for each party to respond to any missed milestones continue to be tolled.

Legal Matters

On October 11, 2018, the Company’s subsidiaries, Enrichment Corp. and American Centrifuge Enrichment, LLC (“ACE”, together with Enrichment Corp., the “Company Subsidiaries”) filed proofs of claim in the U.S. Bankruptcy Court for the Northern District of Ohio (the “Bankruptcy Court”) against each of FirstEnergy Nuclear Operating Company (“FENOC”), FirstEnergy Nuclear Generation, LLC (“FENG,” and together with FENOC, the “FirstEnergy Contract Parties”), FirstEnergy Solutions Corp. (“FES”) and FirstEnergy Generation, LLC (“FG”) in the amount of approximately $314 million. The claims relate to damages arising from the rejection and breach of a long-term contract between the Company Subsidiaries and the FirstEnergy Contract Parties that was approved by the Bankruptcy Court and made effective as of July 26, 2018. The proofs of claim filed by the Company Subsidiaries include claims against FENOC and FENG based on their liability as parties to the contract that was rejected and breached. The proofs of claim filed by the Company Subsidiaries also include claims against FES and FG based on their liability under guaranties they issued that may obligate FES and FG to satisfy the rejection and breach of contract damages claims. No amounts have been recorded in the Company’s consolidated financial statements related to the claims.

Centrus is subject to various legal proceedings and claims, either asserted or unasserted, which arise in the ordinary course of business. While the outcome of these claims cannot be predicted with certainty, other than the above, Centrus does not believe that the outcome of any of these legal matters, individually and in the aggregate, will have a material adverse effect on its cash flows, results of operations or consolidated financial condition.

Lease Commitments

Expenses under operating leases for office space, equipment and the Piketon and Oak Ridge facilities amounted to $3.3 million and $3.1 million in 2018 and 2017, respectively. Future estimated minimum lease payments and expected lease administration payments for leases with remaining terms in excess of one year follow (in millions):



2019	$	0.9
2020	0.9
2021	0.9
2022	1.0
2023	1.0
Thereafter	3.8
	$	8.5

Centrus has a lease with DOE for centrifuge testing facilities in Oak Ridge through December 2019. Centrus leases facilities in Piketon for the American Centrifuge Plant from DOE. The current five-year lease term is through June 2019. Centrus has the option to extend the lease term for additional five-year terms. DOE may terminate the lease for default, including if DOE is able to exercise its remedies with respect to the ACP under the 2002 DOE-USEC Agreement.

Centrus leases the office space for its corporate headquarters in Bethesda, Maryland through October 2027 with an option to extend for five years. In May 2017, Centrus entered into a lease through July 2021 for 6,000 square feet of additional office space in Waverly, Ohio. Centrus also has short-term leases for small areas of office space in Washington, DC and Tokyo, Japan.

Segment Information

12 Months Ended

Dec. 31, 2018

Segment Reporting Information, Revenue for Reportable Segment [Abstract]

Segment Information

Revenue by customer location, including customers in a foreign country representing 10% or more of total revenue, follows (in millions):



	Year Ended December 31,
	2018		2017

United States	$	141.3	$	134.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Total foreign	51.7		83.9
Total revenue	$	193.0	$	218.4

In 2018, the Company’s 10 largest customers represented approximately 85% of total revenue and its three largest customers represented approximately 52% of total revenue. In the Company’s LEU segment, revenue from Florida Power and Light, Synatom, and South Carolina Electric & Gas represented approximately 21%, 18%, 13%, respectively, of total revenue in 2018. In 2017, the Company’s 10 largest customers represented approximately 97% of total revenue and its four largest customers represented approximately 53% of total revenue. In our LEU segment, revenue from Synatom, Entergy, American Electric Power and South Carolina Electric & Gas represented approximately 16%, 14%, 12% and 11%, respectively, of total revenue in 2017. In the Company’s contract services segment, the U.S. government and its contractors represented approximately 12% of total revenue in 2018 and 11% in 2017, respectively. No other customer represented more than 10% of total revenue in 2018 or 2017.

Centrus has two reportable segments: the LEU segment with two components, SWU and uranium, and the contract services segment. The LEU segment includes sales of the SWU component of LEU, sales of both the SWU and uranium components of LEU, and sales of uranium. The contract services segment includes revenue and cost of sales for work that Centrus performs under a fixed price agreement as a contractor to UT-Battelle. The contract services segment also includes limited services provided by Centrus to DOE and its contractors at the Piketon facility. Gross profit is Centrus’ measure for segment reporting. There were no intersegment sales in the periods presented.

The Company’s revenue and gross profit by segment are as follows (in millions):



	Year Ended December 31,
	2018			2017
Revenue
LEU segment:
Separative work units	$	130.6		$	195.4
Uranium	33.8			—
Total	164.4			195.4
Contract services segment	28.6			23.0
Total revenue	$	193.0		$	218.4

Segment Gross Profit (Loss)
LEU segment	$	(23.3	)	$	32.7
Contract services segment	5.4			(2.5		)
Gross profit (loss)	$	(17.9	)	$	30.2

The Company’s total assets are not presented for each reportable segment as they are not reviewed by, nor otherwise regularly provided to, the chief operating decision maker. Centrus’ long-term or long-lived assets, which include property, plant and equipment and other assets reported on the consolidated balance sheet, were located in the United States as of December 31, 2018, and December 31, 2017.

Quarterly Results of Operations

12 Months Ended

Dec. 31, 2018

Quarterly Results of Operations (Unaudited) [Abstract]

Quarterly Financial Information [Text Block]

QUARTERLY RESULTS OF OPERATIONS (Unaudited)

(in millions, except per share data)



	2018
	1st Qtr.			2nd Qtr.			3rd Qtr.			4th Qtr.			Year
Revenue	$	35.7		$	39.4		$	34.1		$	83.8		$	193.0
Cost of sales	41.3			49.8			26.3			93.5			210.9
Gross profit (loss)	(5.6		)	(10.4		)	7.8			(9.7		)	(17.9		)
Advanced technology license and decommissioning costs	7.7			5.7			5.8			6.9			26.1
Selling, general and administrative	11.2			9.7			8.8			10.2			39.9
Amortization of intangible assets	1.3			1.5			1.7			2.1			6.6
Special charges for workforce reductions and advisory costs	0.6			0.3			0.6			0.7			2.2
Gains on sales of assets	(0.1		)	(0.2		)	—			—			(0.3		)
Operating loss	(26.3		)	(27.4		)	(9.1		)	(29.6		)	(92.4		)
Gain on early extinguishment of debt	—			—			—			(0.5		)	(0.5		)
Nonoperating components of net periodic benefit expense (income)	(1.6		)	(1.7		)	(1.6		)	15.5			10.6
Interest expense	1.0			1.0			1.0			1.1			4.1
Investment income	(0.6		)	(0.6		)	(0.7		)	(0.6		)	(2.5		)
Income tax benefit	(0.1		)	—			—			0.1			—
Net loss	$	(25.0	)	$	(26.1	)	$	(7.8	)	$	(45.2	)	$	(104.1	)
Preferred stock dividends - undeclared and cumulative	1.9			2.0			1.9			2.0			7.8
Net loss allocable to common stockholders	$	(26.9	)	$	(28.1	)	$	(9.7	)	$	(47.2	)	$	(111.9	)

Net loss per share - basic and diluted	$	(2.97	)	$	(3.08	)	$	(1.06	)	$	(5.10	)	$	(12.23	)



	2017
	1st Qtr.			2nd Qtr.			3rd Qtr.			4th Qtr.			Year
Revenue	$	7.2		$	44.0		$	50.3		$	116.9		$	218.4
Cost of sales	10.1			48.7			39.0			90.4			188.2
Gross profit (loss)	(2.9		)	(4.7		)	11.3			26.5			30.2
Advanced technology license and decommissioning costs	6.1			4.4			4.5			0.7			15.7
Selling, general and administrative	12.4			9.7			11.0			10.6			43.7
Amortization of intangible assets	1.2			2.0			2.5			4.9			10.6
Special charges for workforce reductions and advisory costs	2.4			2.3			2.4			2.4			9.5
Gains on sales of assets	(1.0		)	(0.7		)	(0.6		)	(2.3		)	(4.6		)
Operating income (loss)	(24.0		)	(22.4		)	(8.5		)	10.2			(44.7		)
Gain on early extinguishment of debt	(33.6		)	—			—			—			(33.6		)
Nonoperating components of net periodic benefit expense (income)	(0.4		)	(0.4		)	(0.3		)	(26.1		)	(27.2		)
Interest expense	2.9			0.7			0.7			1.0			5.3
Investment income	(0.3		)	(0.3		)	(0.4		)	(0.3		)	(1.3		)
Income tax (benefit) expense	(0.2		)	—			—			0.1			(0.1		)
Net income (loss)	$	7.6		$	(22.4	)	$	(8.5	)	$	35.5		$	12.2
Preferred stock dividends - undeclared and cumulative	1.0			2.0			2.0			1.9			6.9
Net income (loss) allocable to common stockholders	$	6.6		$	(24.4	)	$	(10.5	)	$	33.6		$	5.3

Net income (loss) per share:
Basic	$	0.73		$	(2.69	)	$	(1.15	)	$	3.69		$	0.58
Diluted	$	0.72		$	(2.69	)	$	(1.15	)	$	3.69		$	0.58

The calculation of net income (loss) per share on a dilutive basis is provided in Note 14, Net Income (Loss) Per Share. No dilutive effect is recognized in periods in which a net loss has occurred or in which the assumed conversion effect of options or convertible securities is anti-dilutive.

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2018

Summary of Significant Accounting Policies [Abstract]

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

Cash and Cash Equivalents, Policy [Policy Text Block]

Cash and Cash Equivalents

Cash and cash equivalents include short-term or highly liquid assets with original maturities of three months or less.

Inventory, Policy [Policy Text Block]

Inventories and Inventories Owed to Customers and Suppliers

Income Tax, Policy [Policy Text Block]

Deferred Taxes

Property, Plant and Equipment, Policy [Policy Text Block]

Property, Plant and Equipment

Intangible Assets, Policy [Policy Text Block]

Intangible Assets

Fair Value of Financial Instruments, Policy [Policy Text Block]

Financial Instruments and Fair Value Measurement

Revenue Recognition, Policy

Revenue

SWU and Uranium Revenue

Contract Services Revenue

Advanced Technology Costs, Policy [Policy Text Block]

Advanced Technology License and Decommissioning Costs

Pension and Other Postretirement Plans, Policy [Policy Text Block]

Pension and Postretirement Health and Life Benefit Plans

Stock-based Compensation, Policy [Policy Text Block]

Stock-Based Compensation

New Accounting Pronouncements, Policy [Policy Text Block]

New Accounting Standards

Recently Adopted Accounting Standards

The following table summarizes the cumulative effect of the changes to the Company’s consolidated balance sheet as of January 1, 2018, from the adoption of ASC 606 (in millions):



	Balance at December 31, 2017			Adjustment for ASC 606		Balance at January 1, 2018
Assets:
Unbilled contract revenue	$	—		$	0.1	$	0.1
Stockholders’ Deficit:
Accumulated Deficit	(284.5		)	0.1		(284.4		)

The following table summarizes the impact of adopting ASC 606 on revenue and net loss for the year ended December 31, 2018 (in millions):



	Year Ended December 31, 2018
	As Reported			Under Previous Accounting			Effect of Adoption
Revenue	$	193.0		$	193.1		$	(0.1	)
Net loss	(104.1		)	(104.0		)	(0.1		)

The effect of adoption for the year ended December 31, 2018, includes the opening balance adjustment of $0.1 million.



	Year Ended December 31, 2017
	As Previously Reported		Adjustments			Current Presentation
Cost of sales - separative work units and uranium	$	136.1	$	26.6		$	162.7
Selling, general and administrative	43.1		0.6			43.7
Nonoperating components of net periodic benefit expense (income)	—		(27.2		)	(27.2		)

Refer to Note 11, Pension and Postretirement Health and Life Benefits, for additional information.



	Year Ended December 31, 2017
	As Previously Reported			Adjustments			Current Presentation
Cash used in operating activities	$	(25.1	)	$	9.0		$	(16.1	)
Cash used in financing activities	(31.0		)	(9.0		)	(40.0		)

Accounting Standards Effective in Future Periods

Revenue and Contracts with Customers (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Revenue from External Customers by Geographic Areas

The following table presents revenue from SWU and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):



	Year Ended December 31,
	2018		2017
United States	$	112.7	$	111.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Revenue - SWU and uranium	$	164.4	$	195.4

The following table presents revenue from SWU and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):



	Year Ended December 31,
	2018		2017
United States	$	112.7	$	111.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Revenue - SWU and uranium	$	164.4	$	195.4

Revenue by customer location, including customers in a foreign country representing 10% or more of total revenue, follows (in millions):



	Year Ended December 31,
	2018		2017

United States	$	141.3	$	134.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Total foreign	51.7		83.9
Total revenue	$	193.0	$	218.4

Contract with Customer, Asset and Liability

The following table represents changes in the Company’s contract assets and contract liabilities balances (in millions):



	December 31, 2018		January 1, 2018		Year-To-Date Change
Contract assets
Accounts receivable:
Billed	$	50.4	$	60.2	$	(9.8	)
Uranium feed receivable	9.8		—		9.8
Unbilled contract revenue	—		0.1		(0.1		)
Accounts receivable	$	60.2	$	60.3	$	(0.1	)

Deferred costs associated with deferred revenue	$	134.9	$	122.3	$	12.6

Contract liabilities
Deferred revenue and advances from customers - current:
Deferred revenue	$	204.5	$	172.5	$	32.0
Advances from customers	—		19.3		(19.3		)
Deferred revenue and advances from customers - current	$	204.5	$	191.8	$	12.7

Advances from customers - noncurrent	$	15.0	$	—	$	15.0

Deferred cost and deferred revenue activity for the year ended December 31, 2018, follows (in millions):



	Deferred Sales in the Period		Previously Deferred Sales Recognized in the Period			Year-To-Date Change
Deferred costs associated with deferred revenue	$	25.4	$	(12.8	)	$	12.6
Deferred revenue	55.3		(23.3		)	32.0

Special Charges Special Charges (Tables)

12 Months Ended

Dec. 31, 2018

Restructuring and Related Activities [Abstract]

Restructuring and Related Costs

A summary of termination benefit activity and related liabilities follows (in millions):



	Liability Dec. 31, 2016		2017					Liability Dec. 31, 2017		2018					Liability Dec. 31, 2018
	Liability Dec. 31, 2016		Charges for Termination Benefits		Paid/ Settled			Liability Dec. 31, 2017		Charges for Termination Benefits		Paid/ Settled			Liability Dec. 31, 2018
Workforce reductions:
Evolving business needs	$	0.1	$	2.4	$	(1.7	)	$	0.8	$	2.1	$	(2.0	)	$	0.9
Piketon demonstration facility	5.4		1.1		(0.8		)	5.7		0.1		(2.6		)	3.2
Total	$	5.5	$	3.5	$	(2.5	)	$	6.5	$	2.2	$	(4.6	)	$	4.1

Cash, Cash Equivalents and Restricted Cash (Tables)

12 Months Ended

Dec. 31, 2018

Cash, Cash Equivalents and Restricted Cash [Abstract]

Schedule of Cash and Cash Equivalents



	December 31, 2018		December 31, 2017

Cash and cash equivalents	$	123.1	$	208.8
Deposits for financial assurance - current	30.3		16.3
Deposits for financial assurance - noncurrent	6.3		19.7
Total cash, cash equivalents and restricted cash	$	159.7	$	244.8

Restrictions on Cash and Cash Equivalents

The following table provides additional detail regarding the Company’s deposits for financial assurance (in millions):



	December 31, 2018				December 31, 2017
	Current		Long-Term		Current		Long-Term
NRC license	$	16.3	$	—	$	16.1	$	—
DOE lease	13.8		—		—		13.5
Workers compensation	—		6.0		—		5.9
Other	0.2		0.3		0.2		0.3
Total deposits for financial assurance	$	30.3	$	6.3	$	16.3	$	19.7

Inventories (Tables)

12 Months Ended

Dec. 31, 2018

Inventory, Net [Abstract]

Schedule of Inventories

Components of inventories follow (in millions):



	December 31, 2018						December 31, 2017
	Current Assets		Current Liabilities (a)		Inventories, Net		Current Assets		Current Liabilities (a)		Inventories, Net
Separative work units	$	20.1	$	3.6	$	16.5	$	47.2	$	15.0	$	32.2
Uranium	109.6		99.4		10.2		105.9		62.9		43.0
Total	$	129.7	$	103.0	$	26.7	$	153.1	$	77.9	$	75.2


(a)	Inventories owed to customers and suppliers, included in current liabilities, include SWU and uranium inventories owed to fabricators.

Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

A summary of changes in property, plant and equipment follows (in millions):



	December 31, 2017			Additions / (Depreciation)			Retirements			December 31, 2018
Land	$	1.2		$	—		$	—		$	1.2
Leasehold improvements	3.2			—			(0.7		)	2.5
Machinery and equipment	1.3			0.1			(0.4		)	1.0
Other	1.1			—			—			1.1
Property, plant and equipment, gross	6.8			0.1			(1.1		)	5.8
Accumulated depreciation	(1.9		)	(0.8		)	1.1			(1.6		)
Property, plant and equipment, net	$	4.9		$	(0.7	)	$	—		$	4.2

Assets and Property Sold [Table Text Block]

The Company sold assets and property in 2018 and 2017 related to its operations and the American Centrifuge project that were no longer needed (in millions):



	Year Ended December 31,
	2018		2017
Sales of assets and property, net of auction fees and other costs	$	0.4	$	4.8
Less: net carrying value	—		(0.2		)
Gain on sales of assets	$	0.4	$	4.6

Cash proceeds received	$	0.5	$	4.7

Pension and Postretirement Health and Life Benefits (Tables)

12 Months Ended

Dec. 31, 2018

Defined Benefit Plan Disclosure [Line Items]

Schedule of Changes in Projected Benefit Obligations [Table Text Block]

Changes in the projected benefit obligations and plan assets and the funded status of the plans follow:



	Defined Benefit Pension Plans						Postretirement Health and Life Benefit Plans
($ millions)	Year Ended December 31,						Year Ended December 31,
	2018			2017			2018			2017
Changes in Benefit Obligations:
Obligations at beginning of period	$	817.9		$	814.6		$	170.7		$	192.8
Actuarial (gains) losses, net	(50.8		)	32.8			(13.1		)	(24.8		)
Service costs	3.4			3.7			—			—
Interest costs	28.7			32.2			5.8			7.2
Benefits paid	(57.5		)	(59.3		)	(11.8		)	(14.5		)
Lump sum benefits paid	(4.8		)	(2.9		)	—			—
Plan change	—			—			—			10.0
Administrative expenses paid	(3.1		)	(3.2		)	—			—
Obligations at end of period	733.8			817.9			151.6			170.7
Changes in Plan Assets:
Fair value of plan assets at beginning of period	654.6			634.1			1.8			7.7
Actual return on plan assets	(40.2		)	84.4			—			0.1
Company contributions	14.5			1.5			10.0			8.5
Benefits paid	(57.5		)	(59.3		)	(11.8		)	(14.5		)
Lump sum benefits paid	(4.8		)	(2.9		)	—			—
Administrative expenses paid	(3.1		)	(3.2		)	—			—
Fair value of plan assets at end of period	563.5			654.6			—			1.8
Unfunded status at end of period	$	(170.3	)	$	(163.3	)	$	(151.6	)	$	(168.9	)

Amounts recognized in assets and liabilities:
Current liabilities	$	(1.4	)	$	(1.7	)	(15.4		)	(14.7		)
Noncurrent liabilities	(168.9		)	(161.6		)	(136.2		)	(154.2		)
	$	(170.3	)	$	(163.3	)	$	(151.6	)	$	(168.9	)
Amounts in accumulated other comprehensive income (loss), pre-tax:
Prior service cost (credit)	$	—		$	—		$	(2.4	)	$	(2.5	)

Discount rate used to determine benefit obligations at end of period:	4.3		%	3.7		%	4.3		%	3.6		%

Schedule of Net Benefit Costs [Table Text Block]

Components of Net Periodic Benefit Costs and Other Amounts Recognized in Other Comprehensive Income (Loss)



	Defined Benefit Pension Plans						Postretirement Health and Life Benefit Plans
(in millions)	Year Ended December 31,						Year Ended December 31,
	2018			2017			2018			2017
Net Periodic Benefit (Credits) Costs
Service costs	$	3.4		$	3.7		$	—		$	—
Interest costs	28.7			32.2			5.8			7.2
Expected return on plan assets (gains)	(41.0		)	(40.7		)	—			—
Amortization of prior service costs (credits), net	—			—			(0.2		)	(0.1		)
Actuarial (gains) losses, net	30.4			(10.9		)	(13.1		)	(24.9		)
Loss on plan changes resulting from legal settlement	—			—			—			10.0
Net periodic benefit (credits) costs	$	21.5		$	(15.7	)	$	(7.5	)	$	(7.8	)



Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Amortization of prior service (costs) credits, net	$	—	$	—		$	0.2		$	0.1
Total loss recognized in other comprehensive income (loss), pre-tax	$	—	$	—		$	0.2		$	0.1
Total recognized in net periodic benefit costs (income) and other comprehensive income (loss), pre-tax	$	21.5	$	(15.7	)	$	(7.3	)	$	(7.7	)

Schedule of Assumptions Used [Table Text Block]

Assumptions Used to Determine Net Periodic Benefit Costs



	Defined Benefit Pension Plans		Postretirement Health and Life Benefit Plans
	Year Ended December 31,		Year Ended December 31,
	2018	2017	2018	2017
Discount rate	4.3%	3.7%	4.3%	3.6%
Expected return on plan assets	6.8%	6.8%	—	—

Schedule of Health Care Cost Trend Rates [Table Text Block]

Healthcare cost trend rates used to measure postretirement health benefit obligations follow:



	December 31,
	2018	2017
Healthcare cost trend rate for the following year	6.0%	6.5%
Long-term rate that the healthcare cost trend rate gradually declines to	5%	5%
Year that the healthcare cost trend rate is expected to reach the long-term rate	2021	2021

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block]

A one-percentage-point change in the assumed healthcare cost trend rates would have an effect on the postretirement health benefit obligation and costs as follows:



(in millions)	One-Percentage Point
	Increase		Decrease
Postretirement health benefit obligation	$	2.9	$	(2.7	)
Net periodic benefit costs (service and interest cost components only)	$	0.1	$	(0.1	)

Schedule of Allocation of Plan Assets [Table Text Block]

The allocation of plan assets between equity and debt securities and the target allocation range by asset category for the defined benefit pension plans follows:



	December 31,
	2018		2017		2019 Target
Equity securities	48	%	49	%	40	-	60%
Debt securities	49	%	49	%	40	-	60%
Cash	3	%	2	%	0	-	5%
	100	%	100	%



	Defined Benefit Pension Plans
(in millions)	Level 1				Level 2				Level 3				Total
	2018		2017		2018		2017		2018		2017		2018		2017
U.S. government securities	$	—	$	—	$	34.6	$	34.6	$	—	$	—	$	34.6	$	34.6
Corporate debt	—		—		104.7		119.7		—		—		104.7		119.7
Municipal bonds and non-U.S. government securities	—		—		2.0		3.5		—		—		2.0		3.5
Mortgage and asset backed securities	—		—		4.2		0.3		—		—		4.2		0.3
Fair value of investments by hierarchy level	$	—	$	—	$	145.5	$	158.1	$	—	$	—	$	145.5	$	158.1
Investments measured at NAV (a)													416.1		494.7
Accrued interest receivable													1.8		1.9
Unsettled transactions													0.1		(0.1		)
Plan assets													$	563.5	$	654.6



	Postretirement Health and Life Benefit Plans
(in millions)	Level 1				Level 2				Level 3				Total
	2018		2017		2018		2017		2018		2017		2018		2017
Money market funds	$	—	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Bond mutual funds	—		1.8		—		—		—		—		—		1.8
Fair value of investments by hierarchy level	$	—	$	1.8	$	—	$	—	$	—	$	—	$	—	$	1.8

Schedule of Expected Benefit Payments [Table Text Block]

Estimated future benefit plan payments follow (in millions):



	Defined Benefit Pension Plans		Postretirement Health and Life Benefit Plans
2019	$	57.9	$	15.3
2020	56.0		13.9
2021	54.8		13.2
2022	53.6		12.6
2023	52.4		12.1
2024 to 2028	245.1		49.3

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2018

Share-based Compensation [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

A summary of stock-based compensation costs follows (in millions):



	Year Ended December 31,
	2018		2017

Total stock-based compensation costs:
Restricted stock units	$	0.1	$	0.1
Stock options	0.3		0.4
Expense included in selling, general and administrative expense	$	0.4	$	0.5

Total recognized tax benefit	$	—	$	—

Share-based Compensation, Stock Options, Activity [Table Text Block]

A summary of stock option activity follows:



	Stock Options (thousands)	Weighted Average Exercise Price	Weighted Average Remaining Contractual Life in Years	Aggregate Intrinsic Value (millions)

Outstanding at December 31, 2017	425	$4.14	7.3	$0.1
Outstanding at December 31, 2018	425	$4.14	6.3	$—
Exercisable at December 31, 2018	345	$4.11	6.3	$—

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

Stock options outstanding and options exercisable at December 31, 2018, follow:



Stock Exercise Price	Options Outstanding (thousands)	Remaining Contractual Life in Years	Options Exercisable (thousands)

$5.62	22	5.9	22
$4.37	300	6.2	225
$3.90	23	6.6	23
$3.93	15	6.6	15
$2.71	50	6.8	50
$2.68	15	7.4	10

Income Taxes Income Taxes (Tables)

12 Months Ended

Dec. 31, 2018

Income Tax Disclosure [Abstract]

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

Benefit

The benefit from income taxes from continuing operations is as follows (in millions):



	Year Ended December 31,
	2018		2017
Current:
Federal	$	—	$	—
State and local	—		(0.1		)
Foreign	—		—
	—		(0.1		)
Deferred:
Federal	—		—
State and local	—		—
Foreign	—		—
	—		—
	$	—	$	(0.1	)

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

Deferred Taxes



	December 31,
	2018			2017
Deferred tax assets:
Employee benefits costs	$	73.6		$	79.9
Inventory	11.1			2.4
Property, plant and equipment	185.9			187.0
Net operating loss and credit carryforwards	187.1			166.9
Accrued expenses	0.9			0.9
Long-term debt and financing costs	15.3			17.3
Other	0.2			5.5
	474.1			459.9
Valuation allowance	(456.6		)	(440.7		)
Deferred tax assets, net of valuation allowance	$	17.5		$	19.2

Deferred tax liabilities:
Intangible assets	$	16.0		$	17.7
Prepaid expenses	1.5			1.5
Deferred tax liabilities	$	17.5		$	19.2
	$	—		$	—

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Effective Tax Rate

A reconciliation of income taxes calculated based on the federal statutory income tax rate and the effective tax rate follows:



	Year Ended December 31,
	2018		2017
Federal statutory tax rate	21	%	35	%
Valuation allowance against net deferred tax assets	(15	)	(2,156	)
State rate changes	(6	)	—
Executive compensation	(1	)	—
State income tax expense, net of federal benefit	1		1
Tax Cuts and Jobs Act of 2017	—		2,382
Gain on early extinguishment of debt	—		(268	)
Interest expense	—		4
Other non-deductible expenses	—		1
Effective tax rate	—	%	(1	)%

Summary of Income Tax Contingencies [Table Text Block]

A reconciliation of the beginning and ending amount of unrecognized tax benefits follows (in millions):



	Year Ended December 31,
	2018			2017
Balance at beginning of the period	$	0.3		$	0.4
Additions to tax positions of current period	—			0.1
Reductions to tax positions of prior years	(0.1		)	(0.2		)
Balance at end of the period	$	0.2		$	0.3

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Attributable to Parent [Abstract]

Schedule of Stock by Class [Table Text Block]

Changes in the number of shares outstanding are as follows:



	Preferred Stock, Series B	Common Stock, Class A	Common Stock, Class B

Balance at December 31, 2016	—	7,563,600	1,436,400
Issuance of Preferred Stock	104,574	—	—
Issuance of Class A Common Stock	—	38,751	—
Conversion of Common Stock from Class B to Class A	—	30,318	(30,318	)
Balance at December 31, 2017	104,574	7,632,669	1,406,082

Issuance of Class A Common Stock	—	398,638	—
Balance at December 31, 2018	104,574	8,031,307	1,406,082

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 14: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Segment Information (Tables)

12 Months Ended

Dec. 31, 2018

Segment Reporting Information, Revenue for Reportable Segment [Abstract]

Revenue from External Customers by Geographic Areas

The following table presents revenue from SWU and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):



	Year Ended December 31,
	2018		2017
United States	$	112.7	$	111.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Revenue - SWU and uranium	$	164.4	$	195.4

The following table presents revenue from SWU and uranium sales disaggregated by geographical region based on the billing addresses of customers (in millions):



	Year Ended December 31,
	2018		2017
United States	$	112.7	$	111.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Revenue - SWU and uranium	$	164.4	$	195.4

Revenue by customer location, including customers in a foreign country representing 10% or more of total revenue, follows (in millions):



	Year Ended December 31,
	2018		2017

United States	$	141.3	$	134.5
Foreign:
Belgium	35.2		34.9
Japan	3.1		49.0
Other	13.4		—
Total foreign	51.7		83.9
Total revenue	$	193.0	$	218.4

Segment Reporting Information



	Year Ended December 31,
	2018			2017
Revenue
LEU segment:
Separative work units	$	130.6		$	195.4
Uranium	33.8			—
Total	164.4			195.4
Contract services segment	28.6			23.0
Total revenue	$	193.0		$	218.4

Segment Gross Profit (Loss)
LEU segment	$	(23.3	)	$	32.7
Contract services segment	5.4			(2.5		)
Gross profit (loss)	$	(17.9	)	$	30.2

Quarterly Results of Operations (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Results of Operations (Unaudited) [Abstract]

Schedule of Quarterly Financial Information [Table Text Block]

QUARTERLY RESULTS OF OPERATIONS (Unaudited)

(in millions, except per share data)



	2018
	1st Qtr.			2nd Qtr.			3rd Qtr.			4th Qtr.			Year
Revenue	$	35.7		$	39.4		$	34.1		$	83.8		$	193.0
Cost of sales	41.3			49.8			26.3			93.5			210.9
Gross profit (loss)	(5.6		)	(10.4		)	7.8			(9.7		)	(17.9		)
Advanced technology license and decommissioning costs	7.7			5.7			5.8			6.9			26.1
Selling, general and administrative	11.2			9.7			8.8			10.2			39.9
Amortization of intangible assets	1.3			1.5			1.7			2.1			6.6
Special charges for workforce reductions and advisory costs	0.6			0.3			0.6			0.7			2.2
Gains on sales of assets	(0.1		)	(0.2		)	—			—			(0.3		)
Operating loss	(26.3		)	(27.4		)	(9.1		)	(29.6		)	(92.4		)
Gain on early extinguishment of debt	—			—			—			(0.5		)	(0.5		)
Nonoperating components of net periodic benefit expense (income)	(1.6		)	(1.7		)	(1.6		)	15.5			10.6
Interest expense	1.0			1.0			1.0			1.1			4.1
Investment income	(0.6		)	(0.6		)	(0.7		)	(0.6		)	(2.5		)
Income tax benefit	(0.1		)	—			—			0.1			—
Net loss	$	(25.0	)	$	(26.1	)	$	(7.8	)	$	(45.2	)	$	(104.1	)
Preferred stock dividends - undeclared and cumulative	1.9			2.0			1.9			2.0			7.8
Net loss allocable to common stockholders	$	(26.9	)	$	(28.1	)	$	(9.7	)	$	(47.2	)	$	(111.9	)

Net loss per share - basic and diluted	$	(2.97	)	$	(3.08	)	$	(1.06	)	$	(5.10	)	$	(12.23	)



	2017
	1st Qtr.			2nd Qtr.			3rd Qtr.			4th Qtr.			Year
Revenue	$	7.2		$	44.0		$	50.3		$	116.9		$	218.4
Cost of sales	10.1			48.7			39.0			90.4			188.2
Gross profit (loss)	(2.9		)	(4.7		)	11.3			26.5			30.2
Advanced technology license and decommissioning costs	6.1			4.4			4.5			0.7			15.7
Selling, general and administrative	12.4			9.7			11.0			10.6			43.7
Amortization of intangible assets	1.2			2.0			2.5			4.9			10.6
Special charges for workforce reductions and advisory costs	2.4			2.3			2.4			2.4			9.5
Gains on sales of assets	(1.0		)	(0.7		)	(0.6		)	(2.3		)	(4.6		)
Operating income (loss)	(24.0		)	(22.4		)	(8.5		)	10.2			(44.7		)
Gain on early extinguishment of debt	(33.6		)	—			—			—			(33.6		)
Nonoperating components of net periodic benefit expense (income)	(0.4		)	(0.4		)	(0.3		)	(26.1		)	(27.2		)
Interest expense	2.9			0.7			0.7			1.0			5.3
Investment income	(0.3		)	(0.3		)	(0.4		)	(0.3		)	(1.3		)
Income tax (benefit) expense	(0.2		)	—			—			0.1			(0.1		)
Net income (loss)	$	7.6		$	(22.4	)	$	(8.5	)	$	35.5		$	12.2
Preferred stock dividends - undeclared and cumulative	1.0			2.0			2.0			1.9			6.9
Net income (loss) allocable to common stockholders	$	6.6		$	(24.4	)	$	(10.5	)	$	33.6		$	5.3

Net income (loss) per share:
Basic	$	0.73		$	(2.69	)	$	(1.15	)	$	3.69		$	0.58
Diluted	$	0.72		$	(2.69	)	$	(1.15	)	$	3.69		$	0.58

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Prior period reclassification adjustment									$ 0.3
Average useful life of finite-lived intangible assets									15 years
Adoption of ASC 606 as of January 1, 2018									$ 0.1
Unbilled contract revenue	$ 0.0								0.0		$ 0.1
Accumulated deficit	(388.5)				$ (284.5)				(388.5)	$ (284.5)	(284.4)
Revenue									193.0
Net income (loss)	(45.2)	$ (7.8)	$ (26.1)	$ (25.0)	35.5	$ (8.5)	$ (22.4)	$ 7.6	(104.1)	12.2
Cost of sales	93.5	26.3	49.8	41.3	90.4	39.0	48.7	10.1	210.9	188.2
Selling, general and administrative	10.2	8.8	9.7	11.2	10.6	11.0	9.7	12.4	39.9	43.7
Nonoperating components of net periodic benefit expense (income)	$ 15.5	$ (1.6)	$ (1.7)	$ (1.6)	$ (26.1)	$ (0.3)	$ (0.4)	$ (0.4)	10.6	(27.2)
Net cash used in operating activities									(74.4)	(16.1)
Net cash used in financing activities									(11.1)	(40.0)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
Unbilled contract revenue											0.1
Accumulated deficit											$ 0.1
Revenue									(0.1)
Net income (loss)									(0.1)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenue									193.1
Net income (loss)									(104.0)
Product [Member]
Cost of sales									$ 187.7	162.7
Previously Reported [Member]
Selling, general and administrative										43.1
Net cash used in operating activities										(25.1)
Net cash used in financing activities										(31.0)
Previously Reported [Member] \| Product [Member]
Cost of sales										136.1
Restatement Adjustment [Member]
Selling, general and administrative										0.6
Nonoperating components of net periodic benefit expense (income)										(27.2)
Net cash used in operating activities										9.0
Net cash used in financing activities										(9.0)
Restatement Adjustment [Member] \| Product [Member]
Cost of sales										$ 26.6

Revenue and Contracts with Customers (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Advances from customers, noncurrent	$ 15.0	$ 14.5		$ 0.0
Deferred revenue, revenue recognized	23.3
Separative work units owed to others noncurrent	7.3
Accounts receivable, net	60.2		$ 60.3	60.2
Contract with customer, asset, adjustment to contract asset, modification of contract	20.7
Contract with customer, liability, adjustment to contract liability, modification of contract	21.1
Contract with customer, liability, adjustment to contract libility, modification of contract, net	0.4
Government [Member]
Litigation settlement, amount awarded from other party	24.0
Accounts receivable, net				14.5
Proceeds from Customers	4.7
Advances from customers				19.3
Gain (loss) related to litigation settlement	9.5
Low Enriched Uranium Segment [Member]
Revenue, remaining performance obligation, amount	$ 1,000.0			$ 1,300.0

Revenue and Contracts with Customers (Revenue from External Customers by Geographic Areas) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 193.0	$ 218.4
United States
Revenue	141.3	134.5
Belgium
Revenue	35.2	34.9
Japan
Revenue	3.1	49.0
Other Foreign
Revenue	13.4
Product [Member]
Revenue	164.4	195.4
Product [Member] \| United States
Revenue	112.7	111.5
Product [Member] \| Belgium
Revenue	35.2	34.9
Product [Member] \| Japan
Revenue	3.1	49.0
Product [Member] \| Other Foreign
Revenue	$ 13.4	$ 0.0

Revenue and Contracts with Customers (Contract with Customer Asset and Liability) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2018	Jan. 01, 2018
Revenue from Contract with Customer [Abstract]
Billed accounts receivable	$ 50.4	$ 50.4			$ 60.2
Billed accounts receivable – increase (decrease)	(9.8)
Uranium feed receivable	9.8	9.8
Uranium feed receivable - increase (decrease)	9.8
Unbilled contract revenue	0.0	0.0			0.1
Unbilled receivables – increase (decrease)	(0.1)
Accounts receivable, net	60.2	60.2	$ 60.2		60.3
Accounts receivable – increase (decrease)	(0.1)	(9.7)	17.6
Deferred costs associated with deferred revenue	134.9	134.9	122.3		122.3
Deferred costs – increase (decrease)	12.6
Deferred revenue	204.5	204.5			172.5
Deferred revenue – increase (decrease)	32.0
Advances from customers	0.0	0.0			19.3
Customer advances – increase (decrease)	(19.3)
Deferred revenue and advances from customers	204.5	204.5	191.8		$ 191.8
Deferred revenue and customer advances – increase (decrease)	12.7
Advances from customers, noncurrent	15.0	15.0	$ 0.0	$ 14.5
Advances from customers, noncurrent - increase (decrease)	$ 15.0
Deferred costs, additions		25.4
Deferred costs, costs recognized		(12.8)
Deferred revenue, additions		55.3
Deferred revenue, revenue recognized		$ (23.3)

Special Charges (Table) (Details) - USD ($) $ in Millions	12 Months Ended
Special Charges (Table) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Termination benefit costs	$ 2.2	$ 3.5
Payments for one-time termination benefits	(4.6)	(2.5)
Restructuring liability	4.1	6.5	$ 5.5
Contract Termination [Member]
Termination benefit costs	0.1	1.1
Payments for one-time termination benefits	(2.6)	(0.8)
Restructuring liability	3.2	5.7	5.4
Other Restructuring [Member]
Termination benefit costs	2.1	2.4
Payments for one-time termination benefits	(2.0)	(1.7)
Restructuring liability	$ 0.9	$ 0.8	$ 0.1

Special Charges (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Special charges for workforce reductions and advisory costs	$ 0.7	$ 0.6	$ 0.3	$ 0.6	$ 2.4	$ 2.4	$ 2.3	$ 2.4	$ 2.2	$ 9.5
Termination benefit costs									2.2	3.5
Other restructuring costs									0.1	6.3
Contract Termination [Member]
Termination benefit costs									0.1	$ 1.1
Restructuring liability, current	$ 3.2								$ 3.2

Cash, Cash Equivalents and Restricted Cash (Schedule of Cash, Cash Equivalents and Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 123.1	$ 208.8
Restricted cash included in other current assets	30.3	16.3
Restricted cash included in other long-term assets	6.3	19.7
Total cash, cash equivalents and restricted cash	$ 159.7	$ 244.8	$ 296.7

Cash, Cash Equivalents and Restricted Cash (Schedule of Restricted Cash) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in other current assets	$ 30.3	$ 16.3
Restricted cash included in other long-term assets	6.3	19.7
Other financial assurance [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in other current assets	0.2	0.2
Restricted cash included in other long-term assets	0.3	0.3
ARO financial assurance [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in other current assets	16.3	16.1
Workers compensation financial assurance [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in other long-term assets	6.0	5.9
Lease turnover financial assurance [Member]
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash included in other current assets	13.8
Restricted cash included in other long-term assets	$ 13.8	$ 13.5

Cash, Cash Equivalents and Restricted Cash (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Restricted cash included in other current assets	$ 30.3	$ 16.3
Accrued lease turnover costs	1.6	0.8
Restricted cash included in other long-term assets	6.3	19.7
ARO financial assurance [Member]
Restricted cash included in other current assets	16.3	16.1
Lease turnover financial assurance [Member]
Restricted cash included in other current assets	13.8
Restricted cash included in other long-term assets	13.8	13.5
Workers compensation financial assurance [Member]
Restricted cash included in other long-term assets	$ 6.0	$ 5.9

Inventories (Schedule of Inventories) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Inventory, Net [Abstract]
Separative work units inventory	$ 20.1	$ 47.2
Uranium inventory	109.6	105.9
Inventories	129.7	153.1
Separative work units owed to customers and suppliers	3.6	15.0
Uranium owed to customers and suppliers	99.4	62.9
Inventories owed to customers and suppliers	103.0	77.9
Separative work units net of liability	16.5	32.2
Uranium inventory net of liability	10.2	43.0
Inventories, net	$ 26.7	$ 75.2

Property, Plant and Equipment (Tables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5.8	$ 6.8
Property, Plant and Equipment, Additions	0.1
Property, Plant and Equipment, Disposals	(1.1)
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	(1.6)	(1.9)
Depreciation	(0.8)	(1.4)
Accumulated Depreciation, Depletion and Amortization, Sale or Disposal of Property, Plant and Equipment	1.1
Property, Plant And Equipment, Net Capital Expenditures	(0.7)
Property, Plant and Equipment, Net	4.2	4.9
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1.2	1.2
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2.5	3.2
Property, Plant and Equipment, Disposals	(0.7)
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1.0	1.3
Property, Plant and Equipment, Additions	0.1
Property, Plant and Equipment, Disposals	(0.4)
Other Capitalized Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1.1	$ 1.1

Property, Plant and Equipment (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation	$ 0.8	$ 1.4
Sale price assets and property, net	0.4	4.8
Net carrying value of assets retired		(0.2)
Gain (Loss) on Disposition of Property Plant Equipment	0.4	4.6
Proceeds from Sale of Property, Plant, and Equipment	0.5	4.7
Sale proceeds included in accounts receivable	$ 0.1	$ 0.2

Schedule of Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	$ 123.5	$ 123.5
Accumulated intangible asset amortization	(47.5)	(40.8)
Amortizable intangible assets, net	$ 76.0	82.7
Average useful life of finite-lived intangible assets	15 years
Contract-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	$ 54.6	54.6
Accumulated intangible asset amortization	(28.0)	(25.9)
Amortizable intangible assets, net	26.6	28.7
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets, gross	68.9	68.9
Accumulated intangible asset amortization	(19.5)	(14.9)
Amortizable intangible assets, net	$ 49.4	$ 54.0

Intangible Assets Schedule of Intangible Asset Amortization (Details) $ in Millions	Dec. 31, 2018 USD ($)
Intangible Assets Disclosure [Abstract]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 5.4
Finite-Lived Intangible Assets, Amortization Expense, Year Two	8.0
Finite-Lived Intangible Assets, Amortization Expense, Year Three	8.8
Finite-Lived Intangible Assets, Amortization Expense, Year Four	9.7
Finite-Lived Intangible Assets, Amortization Expense, Year Five	8.3
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	35.8
Finite-Lived Intangible Assets, Net	$ 76.0

Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Trade payables	$ 3.9	$ 6.3
Compensation and benefits payable	21.0	17.4
Postretirement health and life benefit obligations - current	15.4	14.7
Accrued severance payments	4.1	3.9
Accrued lease turnover - current	1.6	1.8
Accrued interest payable on debt	0.6	0.2
Other accrued liabilities	5.8	3.9
Accounts payable and accrued liabilities	$ 52.4	$ 48.2

Schedule of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Deferred issuance costs		$ 0.1
Long-term debt, current	$ 32.8	6.1
Long-term debt	120.2	157.5
Senior Notes [Member]
Debt Instrument [Line Items]
Long-term debt, face amount	74.3	74.3
Long-term debt, interest	45.9	52.0
Long-term debt, current	6.1	6.1
Long-term debt	120.2	126.3
Payment in Kind (PIK) Note [Member]
Debt Instrument [Line Items]
Long-term debt, carrying amount		31.3
Long-term debt, current	$ 26.7
Long-term debt		$ 31.2

Debt (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Preferred stock, shares issued	104,574					104,574
Preferred stock, liquidation preference per share	$ 1,000					$ 1,000
Cash paid in exchange						$ 5.1	$ 27.6
Gain on early extinguishment of debt	$ (0.5)	$ 0.0	$ 0.0	$ 0.0	$ (33.6)	(0.5)	(33.6)
Transaction costs							9.0
Write off of deferred financing cost						0.1	0.4
Long-term debt, current	32.8	6.1				32.8	6.1
Subordination to credit facility, facility total	50.0					50.0
Subordination to credit facility, facility maximum net borrowing	$ 40.0					40.0
Payment in Kind (PIK) Note [Member]
Repurchase of debt						$ 6.3	204.9
Debt instrument interest rate	8.00%					8.00%
Long-term debt, carrying amount		31.3					31.3
Long-term debt, current	$ 26.7					$ 26.7
Senior Notes [Member]
Debt instrument interest rate	8.25%					8.25%
Long-term debt, face amount	$ 74.3	74.3				$ 74.3	74.3
Long-term debt, current	$ 6.1	$ 6.1				$ 6.1	$ 6.1

Fair Value Measurements (Financial Instruments Recorded at Fair Value) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Cash and cash equivalents	$ 123.1	$ 208.8
Cash and cash equivalents	123.1	208.8
Deferred compensation asset	1.4	1.4
Deferred compensation obligation	1.4	1.4
Level 1 [Member]
Cash and cash equivalents	123.1	208.8
Deferred compensation asset	1.4	1.4
Deferred compensation obligation	$ 1.4	$ 1.4

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, current	$ 32.8	$ 6.1
Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt, long-term and short-term, combined carrying value	126.3	132.4
Long-term debt, current	6.1	6.1
Long-term debt, fair value	57.9	61.7
Long-term debt, face amount	74.3	74.3
Payment in Kind (PIK) Note [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, current	26.7
Long-term debt, carrying amount		31.3
Long-term debt, fair value	$ 21.8	$ 25.1

Pension and Postretirement Health and Life Benefits (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan, Accumulated Benefit Obligation	$ 733.8	$ 817.9
Expected defined benefit plan contributions for next fiscal year for qualified plans	9.4
Expected defined benefit plan contributions for next fiscal year for non-qualified plans	1.4
Expected defined benefit plan contributions for next fiscal year for postretirement health and life benefit plans	15.3
Defined Contribution Plan, Cost	1.8	2.3
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	$ (17.3)	25.8
Pension Plan, Defined Benefit [Member]
Approximate Number of Plan Participants	5,000
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	$ (50.8)	$ 32.8
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	3.70%
Other Postretirement Benefits Plan [Member]
Approximate Number of Plan Participants	3,100
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	$ (13.1)	$ (24.8)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	3.60%

Pension and Postretirement Health and Life Benefits (Schedule of Changes in Projected Benefit Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	$ (17.3)	$ 25.8
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Benefit Obligation	733.8	817.9	$ 814.6
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	(50.8)	32.8
Defined Benefit Plan, Service Cost	3.4	3.7
Defined Benefit Plan, Interest Cost	28.7	32.2
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(57.5)	(59.3)
Defined Benefit Plan, Lump Sum Benefits Paid	(4.8)	(2.9)
Defined Benefit Plan, Benefit Obligation, Administrative Expenses Paid	(3.1)	(3.2)
Defined Benefit Plan, Plan Assets, Amount	563.5	654.6	634.1
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	(40.2)	84.4
Defined Benefit Plan, Plan Assets, Contributions by Employer	14.5	1.5
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(170.3)	(163.3)
Amounts Recognized In Current Liabilities	(1.4)	(1.7)
Amounts Recognized In Noncurrent Liabilities	(168.9)	(161.6)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	$ (170.3)	$ (163.3)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	3.70%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Benefit Obligation	$ 151.6	$ 170.7	192.8
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	(13.1)	(24.8)
Defined Benefit Plan, Interest Cost	5.8	7.2
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(11.8)	(14.5)
Defined Benefit Plan, Benefit Obligation, Increase for Plan Amendment		10.0
Defined Benefit Plan, Plan Assets, Amount		1.8	$ 7.7
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)		0.1
Defined Benefit Plan, Plan Assets, Contributions by Employer	10.0	8.5
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(151.6)	(168.9)
Amounts Recognized In Current Liabilities	(15.4)	(14.7)
Amounts Recognized In Noncurrent Liabilities	(136.2)	(154.2)
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position	(151.6)	(168.9)
Recognized In Accumulated Other Comprehensive Income Pre Tax Prior Service Cost Credit	(2.4)	(2.5)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	$ 0.2	$ 0.1
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	3.60%

Pension and Postretirement Health and Life Benefits (Schedule of Net Benefit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	$ (17.3)	$ 25.8
Pension Plan, Defined Benefit [Member]
Service costs	3.4	3.7
Interest costs	28.7	32.2
Expected return on plan assets (gains)	(41.0)	(40.7)
Actuarial (gains) losses, net	30.4	(10.9)
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	(50.8)	32.8
Net periodic benefit cost (credit)	21.5	(15.7)
Postretirement Health and Life Benefits Plans [Member]
Interest costs	5.8	7.2
Amortization of prior service costs (credits), net	(0.2)	(0.1)
Actuarial (gains) losses, net	(13.1)	(24.9)
Defined Benefit Plan, Actuarial (Gain) Loss From Remeasurement	(13.1)	(24.8)
Loss on plan changes resulting from legal settlement		10.0
Net periodic benefit cost (credit)	$ (7.5)	$ (7.8)

Pension and Postretirement Health and Life Benefits (Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	$ (0.2)	$ (0.1)
Pension Plan, Defined Benefit [Member]
Total recognized in net periodic benefit costs (income) and other comprehensive income (loss), pre-tax	21.5	(15.7)
Other Postretirement Benefits Plan [Member]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	0.2	0.1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	0.2	0.1
Total recognized in net periodic benefit costs (income) and other comprehensive income (loss), pre-tax	$ (7.3)	$ (7.7)

Pension and Postretirement Health and Life Benefits (Schedule of Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.30%	3.70%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.80%	6.80%
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	4.30%	3.60%

Pension and Postretirement Health and Life Benefits (Schedule of Healthcare Cost Trend Rates) (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Assumed Health Care Cost Trend Rates [Abstract]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year	6.00%	6.50%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate	2021	2021

Pension and Postretirement Health and Life Benefits (Schedule of Effect of One Percentage Point Change In Assumed Health Care Cost Trend Rates) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rate [Abstract]
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	$ 2.9
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	(2.7)
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	0.1
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	$ (0.1)

Pension and Postretirement Health and Life Benefits (Plan Asset Allocations) (Details)	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	100.00%	100.00%
Equity Securities [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	48.00%	49.00%
Equity Securities [Member] \| Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%
Equity Securities [Member] \| Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	60.00%
Debt Securities [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	49.00%	49.00%
Debt Securities [Member] \| Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%
Debt Securities [Member] \| Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	60.00%
Cash [Member]
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage	3.00%	2.00%
Cash [Member] \| Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Cash [Member] \| Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%

Pension and Postretirement Health and Life Benefits (Schedule of Fair Value of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Pension Plan, Defined Benefit [Member]
US Government Securities	$ 34.6	$ 34.6
Corporate Debt	104.7	119.7
Municipal Bonds	2.0	3.5
Mortgage and asset backed securities	4.2	0.3
Fair Value of Investments by Hierarchy Level	145.5	158.1
Accrued Interest Receivable	1.8	1.9
Unsettled Transactions Receivable	0.1	(0.1)
Defined Benefit Plan, Plan Assets, Amount	563.5	654.6	$ 634.1
Other Postretirement Benefits Plan [Member]
Bond Mutual Funds		1.8
Fair Value of Investments by Hierarchy Level		1.8
Defined Benefit Plan, Plan Assets, Amount		1.8	$ 7.7
Level 1 [Member] \| Other Postretirement Benefits Plan [Member]
Bond Mutual Funds		1.8
Fair Value of Investments by Hierarchy Level		1.8
Fair Value, Inputs, Level 2 [Member] \| Pension Plan, Defined Benefit [Member]
US Government Securities	34.6	34.6
Corporate Debt	104.7	119.7
Municipal Bonds	2.0	3.5
Mortgage and asset backed securities	4.2	0.3
Fair Value of Investments by Hierarchy Level	$ 145.5	$ 158.1

Pension and Postretirement Health and Life Benefits (Schedule of Estimated Future Benefit Payments) (Details) $ in Millions	Dec. 31, 2018 USD ($)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	$ 57.9
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	56.0
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	54.8
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	53.6
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	52.4
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	245.1
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	15.3
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	13.9
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	13.2
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	12.6
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	12.1
Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter	$ 49.3

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2014
Common Stock, Capital Shares Reserved for Future Issuance	596,000		1,200,000
Shares for Cancelled or Forfeited Awards	120,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 0.1
Weighted-average period in years of costs to be recognized	3 months
Restricted stock units potentially converted to common stock shares	141,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	6 years 3 months 19 days	7 years 3 months 19 days
Employee Stock Option [Member]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 0.1

Stock-Based Compensation (Stock-Based Compensation Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation [Abstract]
Restricted Stock or Unit Expense	$ 0.1	$ 0.1
Stock or Unit Option Plan Expense	0.3	0.4
Allocated Share-based Compensation Expense	$ 0.4	$ 0.5

Stock-Based Compensation (Options) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation [Abstract]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 4.14	$ 4.14
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price	$ 4.11
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	425	425
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	345
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value		$ 0.1
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	6 years 3 months 19 days	7 years 3 months 19 days

Schedule of Share Based Compensation Shares Authorized Under Stock Option Plans By Exercise Price (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 4.14	$ 4.14
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	345
Option Group One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 5.62
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	22
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	5 years 10 months 25 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	22
Option Group Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 4.37
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	300
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	6 years 2 months 12 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	225
Option Group Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 3.90
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	23
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	6 years 7 months 6 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	23
Option Group Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 3.93
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	15
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	6 years 7 months 6 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	15
Option Group Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 2.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	6 years 9 months 18 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	50
Option Group Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price	$ 2.68
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options	15
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term	7 years 4 months 24 days
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options	10

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Asset, Increase (Decrease), Amount						$ 288.9
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent					(15.00%)	(2156.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent					(6.00%)	2382.00%
Effective Income Tax Rate Reconciliation, Gain on Early Extinguishment of Debt, Percent						(268.00%)
Increase (decrease) in deferred tax asset valuation allowance					$ 15.9	$ 261.5
Operating Loss Carryforwards			$ 791.3			791.3
Cancellation of debt income for tax					15.3	32.5
Annual limitation of NOL carryforwards and tax credits generated prior to ownership change					2.9
Provision (benefit) for income taxes	$ (0.1)	$ 0.1	(0.1)	$ 0.2	0.0	0.1
Other Comprehensive Income (Loss), Tax					0.0	0.0
Liability for Uncertain Tax Positions, Noncurrent	0.2		0.3		0.2	0.3	$ 0.4
Income Tax Examination, Penalties and Interest Expense Reduction					(0.1)	(0.1)
Unrecognized Tax Benefits, Income Tax Penalties Expense Reduction					(0.1)
Income Tax Examination, Penalties and Interest Accrued	0.1		$ 0.1		$ 0.1	$ 0.1
Federal Statutory Income Tax Rate, Percent					21.00%	35.00%
Domestic Tax Authority [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent						2382.00%
State and Local Jurisdiction [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent					(6.00%)
Increase (decrease) in deferred tax asset valuation allowance					$ 6.0
Operating Loss Carryforwards	0.3				0.3
Tax Year 2018 [Member]
Operating Loss Carryforwards	89.2				89.2
Business Interest Expense Carryforward	$ 10.1				$ 10.1

Income Taxes (Taxes by Jurisdiction) (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Current Income Tax Expense (Benefit)						$ (0.1)
Provision (benefit) for income taxes	$ 0.1	$ (0.1)	$ 0.1	$ (0.2)	$ 0.0	(0.1)
State and Local Jurisdiction [Member]
Current Income Tax Expense (Benefit)						$ (0.1)

Income Taxes (Deferred Income Taxes) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Components of Deferred Tax Assets and Liabilities [Abstract]
Deferred Tax Assets, Employee Benefits Costs	$ 73.6	$ 79.9
Deferred Tax Assets, Inventory	11.1	2.4
Deferred Tax Assets, Property, Plant and Equipment	185.9	187.0
Deferred Tax Assets, Net Operating Loss and Credit Carryforwards	187.1	166.9
Deferred Tax Assets, Accrued Expenses	0.9	0.9
Deferred Tax Assets, Depleted Uranium and Stored Wastes	15.3	17.3
Deferred Tax Assets, Other	0.2	5.5
Deferred Tax Assets, Gross	474.1	459.9
Deferred Tax Assets, Valuation Allowance	(456.6)	(440.7)
Deferred Tax Assets, Net of Valuation Allowance	17.5	19.2
Deferred Tax Liabilities, Intangible Assets	16.0	17.7
Deferred Tax Liabilities, Prepaid Expenses	1.5	1.5
Deferred Tax Liabilities	$ 17.5	$ 19.2

Income Taxes (Rate Reconciliation) (Details)	12 Months Ended
Income Taxes (Rate Reconciliation) (Details)	Dec. 31, 2018	Dec. 31, 2017
Federal Statutory Income Tax Rate, Percent	21.00%	35.00%
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	(15.00%)	(2156.00%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(6.00%)	2382.00%
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent	(1.00%)
Effective Income Tax Rate Reconciliation, State Income Tax Expense, Net of Federal Benefit, Percent	1.00%	1.00%
Effective Income Tax Rate Reconciliation, Gain on Early Extinguishment of Debt, Percent		(268.00%)
Effective Income Tax Rate Reconciliation, Interest Expense, Percent		4.00%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent		1.00%
Effective Income Tax Rate Reconciliation, Percent		(1.00%)
Domestic Tax Authority [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		2382.00%
State and Local Jurisdiction [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	(6.00%)

Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Liability for Uncertain Tax Positions, Noncurrent	$ 0.2	$ 0.3	$ 0.4
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions		0.1
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions	$ (0.1)	$ (0.2)

Net Income Per Share (Schedule of Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Income Per Share Calculation [Line Items]
Net income (loss)	$ (45.2)	$ (7.8)	$ (26.1)	$ (25.0)	$ 35.5	$ (8.5)	$ (22.4)	$ 7.6	$ (104.1)	$ 12.2
Preferred stock dividends, undeclared and cumulative	2.0	1.9	2.0	1.9	1.9	2.0	2.0	1.0	7.8	6.9
Net income (loss) allocable to common stockholders	$ (47.2)	$ (9.7)	$ (28.1)	$ (26.9)	$ 33.6	$ (10.5)	$ (24.4)	$ 6.6	$ (111.9)	$ 5.3
Weighted average number of shares outstanding, basic									9,151	9,081
Potentially dilutive shares related to stock options									0	0
Weighted average number of shares outstanding, diluted									9,151	9,081
Net loss per share - basic and diluted	$ (5.10)	$ (1.06)	$ (3.08)	$ (2.97)					$ (12.23)	$ 0.58
Antidilutive securities excluded from computation of earnings per share									23	0
Options with exercise price greater than market price									360	200

Stockholders' Equity (Tables) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Stock issued during period	$ 0.8	$ 4.6
Common Stock, Shares, Issued	9,437,389
Preferred Stock, Shares Issued	104,574
Preferred Stock, Shares Outstanding	104,574	104,574
Preferred Series B [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues		104,574
Preferred Stock, Shares Issued	104,574	104,574
Common Class A [Member]
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	8,031,307	7,632,669	7,563,600
Conversion of Stock, Shares Converted		30,318
Stock Issued During Period, Shares, New Issues	398,638	38,751
Stock issued during period	$ 0.8
Common Stock, Shares, Issued	8,031,307	7,632,669
Common Class B [Member]
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	1,406,082	1,406,082	1,436,400
Conversion of Stock, Shares Converted		(30,318)
Common Stock, Shares, Issued	1,406,082	1,406,082

Stockholders' Equity (Narrative) (Details) - USD ($)	12 Months Ended
Stockholders' Equity (Narrative) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2014
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	20,000,000	20,000,000
Preferred Stock, Par Value Per Share	$ 1.00	$ 1.00
Preferred Stock, Shares Issued	104,574
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Common Stock, Shares, Issued	9,437,389
Common Stock, Capital Shares Reserved for Future Issuance	596,000		1,200,000
Operating Loss Carryforwards		$ 791,300,000
Common Stock Ownership Enabling Preferred Stock Purchase Rights	4.99%
Common Stock Ownership Enabling Preferred Stock Purchase Rights, Incremental	0.50%
Common Class A [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	70,000,000	70,000,000
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares, Issued	8,031,307	7,632,669
Stock Issued During Period, Shares, New Issues	398,638	38,751
Conversion of Stock, Shares Converted		30,318
Common Stock, Capital Shares Reserved for Future Issuance	596,000		1,200,000
Common Class B [Member]
Class of Stock [Line Items]
Common Stock, Shares Authorized	30,000,000	30,000,000
Common Stock, Par or Stated Value Per Share	$ 0.10	$ 0.10
Common Stock, Shares, Issued	1,406,082	1,406,082
Conversion of Stock, Shares Converted		(30,318)
Preferred Series B [Member]
Class of Stock [Line Items]
Preferred Stock, Par Value Per Share	$ 1.00
Preferred Stock, Shares Issued	104,574	104,574
Preferred Stock, Liquidation Preference Per Share	$ 1,000
Preferred stock	$ 4,600,000	$ 4,600,000
Preferred Stock, Dividend Rate, Percentage	7.50%	7.50%
Stock Issued During Period, Shares, New Issues		104,574
Preferred stock dividend condition - minimum pension funding	90.00%
Preferred stock dividend condition - minimum net income preceding quarter	$ 7,500,000
Preferred stock dividend condition - minimum free cash flow preceding four quarters	35,000,000
Preferred stock dividend condition - minimum cash balance preceding quarter	150,000,000
Preferred Stock, Liquidation Preference, Value	119,300,000	$ 111,500,000
Preferred Stock, Cumulative Undeclared Dividend	$ 14,700,000	$ 6,900,000

Operating Lease Liabilities, Payments Due (Details) $ in Millions	Dec. 31, 2018 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 0.9
Lessee, Operating Lease, Liability, Payments, Due Year Two	0.9
Lessee, Operating Lease, Liability, Payments, Due Year Three	0.9
Lessee, Operating Lease, Liability, Payments, Due Year Four	1.0
Lessee, Operating Lease, Liability, Payments, Due Year Five	1.0
Lessee, Operating Lease, Liability, Payments, Due after Year Five	3.8
Lessee, Operating Lease, Liability, Payments, Due	$ 8.5

Commitment and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Bankruptcy claim filed, unrecorded gain contingency,		$ 314.0
Operating leases, rent expense		$ 3.3	$ 3.1
Scenario, Forecast [Member]
Costs and expenses, related party	$ 7.1

Revenue by Geographic Area (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenue	$ 193.0	$ 218.4
United States
Revenue	141.3	134.5
Belgium
Revenue	35.2	34.9
Japan
Revenue	3.1	49.0
Other Foreign
Revenue	13.4
Total foreign
Revenue	$ 51.7	$ 83.9

Segment Information (Segment Reporting Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue									$ 193.0	$ 218.4
Gross Profit	$ (9.7)	$ 7.8	$ (10.4)	$ (5.6)	$ 26.5	$ 11.3	$ (4.7)	$ (2.9)	(17.9)	30.2
Low Enriched Uranium Segment [Member]
Segment Reporting Information [Line Items]
Revenue									164.4	195.4
Gross Profit									(23.3)	32.7
Contract Services Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit									5.4	(2.5)
Separative Work Units [Member]
Segment Reporting Information [Line Items]
Revenue									130.6	195.4
Uranium [Member]
Segment Reporting Information [Line Items]
Revenue									33.8	0.0
Service [Member]
Segment Reporting Information [Line Items]
Revenue									$ 28.6	$ 23.0

Segment Information (Narrative) (Details)	12 Months Ended
Segment Information (Narrative) (Details)	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Revenue from top 10 customers	85.00%	97.00%
Revenue from top 3 customers	52.00%	53.00%
Revenue from first customer over 10 percent	21.00%	16.00%
Revenue from second customer over 10 percent	18.00%	14.00%
Revenue from third customer over 10 percent	13.00%	12.00%
Revenue from fourth customer over 10 percent		11.00%

Quarterly Results of Operations (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Total Revenue									$ 193.0
Revenue	$ 83.8	$ 34.1	$ 39.4	$ 35.7	$ 116.9	$ 50.3	$ 44.0	$ 7.2	193.0	$ 218.4
Cost of sales									210.9	188.2
Cost of sales	93.5	26.3	49.8	41.3	90.4	39.0	48.7	10.1	210.9	188.2
Gross profit (loss)	(9.7)	7.8	(10.4)	(5.6)	26.5	11.3	(4.7)	(2.9)	(17.9)	30.2
Advanced technology license and decommissioning costs	6.9	5.8	5.7	7.7	0.7	4.5	4.4	6.1	26.1	15.7
Selling, general and administrative	10.2	8.8	9.7	11.2	10.6	11.0	9.7	12.4	39.9	43.7
Amortization of intangible assets	2.1	1.7	1.5	1.3	4.9	2.5	2.0	1.2	6.6	10.6
Special charges for workforce reductions and advisory costs	0.7	0.6	0.3	0.6	2.4	2.4	2.3	2.4	2.2	9.5
Other (income)			(0.2)	(0.1)	(2.3)	(0.6)	(0.7)	(1.0)	(0.3)	(4.6)
Operating (loss)	(29.6)	(9.1)	(27.4)	(26.3)	10.2	(8.5)	(22.4)	(24.0)	(92.4)	(44.7)
Gain on early extinguishment of debt	(0.5)				0.0	0.0	0.0	(33.6)	(0.5)	(33.6)
Nonoperating components of net periodic benefit expense (income)	15.5	(1.6)	(1.7)	(1.6)	(26.1)	(0.3)	(0.4)	(0.4)	10.6	(27.2)
Interest expense	1.1	1.0	1.0	1.0	1.0	0.7	0.7	2.9	4.1	5.3
Investment income	(0.6)	(0.7)	(0.6)	(0.6)	(0.3)	(0.4)	(0.3)	(0.3)	(2.5)	(1.3)
Provision (benefit) for income taxes	0.1			(0.1)	0.1			(0.2)	0.0	(0.1)
Net income (loss)	(45.2)	(7.8)	(26.1)	(25.0)	35.5	(8.5)	(22.4)	7.6	(104.1)	12.2
Preferred stock dividends, undeclared and cumulative	2.0	1.9	2.0	1.9	1.9	2.0	2.0	1.0	7.8	6.9
Net income (loss) allocable to common stockholders	$ (47.2)	$ (9.7)	$ (28.1)	$ (26.9)	$ 33.6	$ (10.5)	$ (24.4)	$ 6.6	$ (111.9)	$ 5.3
Net income (loss) per common share - basic					$ 3.69	$ (1.15)	$ (2.69)	$ 0.73		$ 0.58
Net income (loss) per common share - diluted					$ 3.69	$ (1.15)	$ (2.69)	$ 0.72		0.58
Net loss per share - basic and diluted	$ (5.10)	$ (1.06)	$ (3.08)	$ (2.97)					$ (12.23)	$ 0.58

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
Accumulated Other Comprehensive Income (Loss)	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The sole component of accumulated other comprehensive income (loss) (“AOCI”) relates to activity in the accounting for pension and postretirement health and life benefit plans. The amortization of prior service costs (credits) are reclassified from AOCI and included in the computation of net periodic benefit cost as detailed in Note 11, Pension and Postretirement Health and Life Benefits.