Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation and Principles of Consolidation The consolidated financial statements of Centrus Energy Corp. (“Centrus” or the “Company”) were prepared in conformity with generally accepted accounting principles in the U.S. (“U.S. GAAP”). The consolidated financial statements include the accounts of Centrus, its principal subsidiary United States Enrichment Corporation (“Enrichment Corp.”), and its other subsidiaries. All material intercompany transactions are eliminated.
Use of Estimates, Policy [Policy Text Block]	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, American Centrifuge decontamination and decommissioning obligations, 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, 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 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 monthly moving 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.
Income Tax, Policy [Policy Text Block]	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, Policy [Policy Text Block]	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, Policy [Policy Text Block]	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, Policy [Policy Text Block]	Carrying Value of Long-Lived Assets The carrying values of property, plant and equipment and identifiable intangible assets are subject to impairment tests whenever adverse conditions or changes in circumstances indicate a possible impairment loss. Impairment tests are based on a comparison of estimated future cash flows to the carrying value of long-lived assets. If impairment is indicated, the asset carrying value is reduced to its fair value and an impairment loss is recognized.
Fair Value of Financial Instruments, Policy [Policy Text Block]	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 “8.0% 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 8.0% 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.
Revenue Recognition, Policy [Policy Text Block]	SWU and Uranium Revenue Revenue 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. Revenue is recognized at the time LEU or uranium is delivered under the terms of contracts with domestic and international electric utility customers. Most customers take title and delivery of LEU at 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. Revenue is recognized when delivery of LEU to the customer occurs at the fuel fabricator. Utility customers in general have the option to defer physical receipt of LEU or uranium purchased from us beyond the contractual sale period. In such cases, title to LEU or uranium is transferred to the customer and an obligation for Centrus is created and a receivable is recorded. Cash is collected for the receivable under normal credit terms. The obligation is included in Deferred Revenue and Advances from Customers on the consolidated balance sheet and the customer-titled product is classified as Deferred Costs Associated with Deferred Revenue. Risk of loss remains with Centrus until physical delivery occurs. The recognition of revenue and related cost of sales occurs at the time physical delivery occurs and risk of loss transfers to the customer, which may occur beyond one year. The timing of physical delivery, 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, Centrus will accept payment in the form of uranium. Revenue from the sale of SWU under such contracts is recognized at the time LEU is delivered and is based on the fair value of the uranium received in exchange for the SWU. Contract Services Revenue The contract services segment consists primarily of revenue and cost of sales for engineering and testing work Centrus performs under an agreement with UT-Battelle, LLC (“UT-Battelle”), the management and operating contractor for Oak Ridge National Laboratory (“ORNL”). The contract services segment also includes limited services provided by Centrus to the U.S. Department of Energy (“DOE”) and its contractors at the Portsmouth site related to facilities the Company leases from DOE. Contract services revenue includes billings for fees and payments for allowable costs that are determined in accordance with the terms of the underlying contracts. The contracts with UT-Battelle provide for fixed payments for monthly reports or for fixed payments upon completion of milestones. For contracts that provide fixed payments for monthly reports, revenue is recognized as deliverables are completed and as fees are earned. For contracts that provide fixed payments for completion of milestones, revenue is recognized as each milestone is completed. 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 at the Portsmouth and Paducah sites. 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.
Advanced Technology Costs, Policy [Policy Text Block]	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. In the second quarter of 2016, the Company commenced with the decontamination and decommissioning (“D&D”) of the Piketon facility in accordance with NRC requirements. Refer to Note 3, Contract Services and Advanced Technology License and Decommissioning Costs, and Note 16, Commitments and Contingencies, for further details regarding the American Centrifuge project.
Pension and Other Postretirement Plans, Policy [Policy Text Block]	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.
Share-based Compensation, Policy [Policy Text Block]	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 Pronouncements, Policy [Policy Text Block]	New Accounting Standards In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers (Topic 606). ASU 2014-09 introduces a new five-step revenue recognition model in which an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 also requires disclosures sufficient to enable users to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, including qualitative and quantitative disclosures about contracts with customers, significant judgments and changes in judgments, and assets recognized from the costs to obtain or fulfill a contract. The FASB issued amendments in 2015 and 2016 that provide clarification on a number of specific issues as well as requiring additional disclosures. The revenue recognition standard will become effective for the Company beginning with the first quarter of 2018. The Company has determined that this standard will not have a material impact on its financial position or results of operations. The Company adopted FASB ASU No. 2014-09 on January 1, 2018 using the modified retrospective method. 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 finance or operating, with classification affecting expense recognition in the statement of operations. ASU 2016-02 is effective for the Company in the first quarter of 2019, with early adoption permitted, and is to be applied using a modified retrospective approach. The Company is evaluating the effect that the provisions of ASU 2016-02 will have on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Stock Compensation - Improvements to Employee Share-Based Payment Accounting (Topic 718). ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 became effective for the Company beginning in the first quarter of 2017. Under ASU 2016-09, entities are permitted to make an accounting policy election to either estimate forfeitures on share-based payment awards, as previously required, or to recognize forfeitures as they occur. The Company has elected to recognize forfeitures as they occur. The adoption of ASU 2016-09 did not have a material impact on the Company’s consolidated financial statements. 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 is effective for the Company beginning in the first quarter of 2018, and is to be applied retrospectively. Under the retrospective transition, transaction costs of $9.0 million incurred in the three months ended March 31, 2017, related to the February 14, 2017, securities exchange described in Note 9, Debt, will be reclassified from cash used in operating activities to cash used in financing activities. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory, requiring an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs. ASU 2016-09 is effective for the Company beginning in the first quarter of 2018. The provisions of ASU 2016-16 are not expected to have a material impact on the Company’s consolidated financial statements. 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, and is effective for the Company beginning in the first quarter of 2018. The provisions of ASU 2016-18 are not expected to have a material impact on the Company’s consolidated financial statements. 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 the service cost component of net periodic benefit costs be presented with other employee compensation costs and other components of net periodic benefit costs to be presented outside of any subtotal of operating income. In addition, only the service cost component of net periodic benefit costs is eligible for capitalization in assets when applicable. ASU 2017-07 will become effective for the Company beginning in the first quarter of 2018. The provisions of ASU 2017-17 related to the presentation of the components of net periodic benefit costs are to be applied retrospectively. Annual net periodic benefit costs (credits) of ($26.5 million) and ($0.7 million) for 2017 will be reclassified from cost of sales and selling, general and administrative (SG&A) expense, respectively, to other nonoperating income in the consolidated statement of operations. The provision of ASU 2017-17 allowing only the service cost component of net periodic benefit costs to be capitalized will be adopted on a prospective basis and is not expected to have a significant impact on the Company’s consolidated financial statements as no portion of net periodic benefit costs were capitalized in assets during 2017. 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. ASU 2018-02 allows a reclassification from accumulated other comprehensive income to retained earnings for the tax effects of items within accumulated other comprehensive income (stranded tax effects) resulting from the decrease in the corporate income tax rate reflected in the December 2017 Tax Cuts and Jobs Act. The provisions of ASU 2018-02 are effective for all fiscal years beginning after December 15, 2018 and interim periods within those years. Early adoption is permitted. The Company is evaluating the effects that ASU 2018-02 will have its consolidated financial statements.