Aleris 10-Q4 May 172017 Q1 Quarterly reportFinancial data

Company Profile

Document And Entity Information

Document And Entity Information	3 Months Ended
Document And Entity Information	Mar. 31, 2017shares
Document And Entity Information [Abstract]
Entity Registrant Name	Aleris Corporation
Entity Central Index Key	1,518,587
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	31,989,712

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 74.6	$ 55.6
Accounts receivable (net of allowances of $7.0 and $7.6 at March 31, 2017 and December 31, 2016, respectively)	271.3	218.7
Inventories	610.2	538.9
Prepaid expenses and other current assets	36.6	33.4
Total Current Assets	992.7	846.6
Property, plant and equipment, net	1,375.2	1,346
Intangible assets, net	36.3	36.8
Deferred income taxes	91.9	88.3
Other long-term assets	67.6	72.2
Total Assets	2,563.7	2,389.9
Current Liabilities
Accounts payable	294.1	246.6
Accrued liabilities	224.6	201.4
Current portion of long-term debt	28.5	27.7
Total Current Liabilities	547.2	475.7
Long-term debt	1,564.8	1,438.5
Deferred income taxes	9.2	2.8
Accrued pension benefits	159.8	158.4
Accrued postretirement benefits	33.6	34.2
Other long-term liabilities	63.2	63.7
Total Long-Term Liabilities	1,830.6	1,697.6
Stockholders’ Equity
Common stock; par value $.01; 45,000,000 shares authorized and 31,989,712 and 31,904,250 shares issued at March 31, 2017 and December 31, 2016, respectively	0.3	0.3
Preferred stock; par value $.01; 1,000,000 shares authorized; none issued	0	0
Additional paid-in capital	427.5	428
Retained (deficit) earnings	(28)	11.8
Accumulated other comprehensive loss	(213.9)	(223.5)
Total Equity	185.9	216.6
Total Liabilities and Equity	$ 2,563.7	$ 2,389.9

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 7	$ 7.6
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	45,000,000	45,000,000
Common stock, shares issued	31,989,712	31,904,250
Common stock, shares outstanding	31,989,712	31,904,250
Redeemable preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Redeemable preferred stock, shares authorized	1,000,000	1,000,000
Redeemable preferred stock, shares issued	0	0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Statement [Abstract]
Revenues	$ 674.2	$ 662.5
Cost of sales	589.1	589
Gross profit	85.1	73.5
Selling, general and administrative expenses	53.2	50.3
Restructuring charges	0.4	0.8
Losses (gains) on derivative financial instruments	28.2	(1)
Other operating expense, net	1	0.4
Operating income	2.3	23
Interest expense, net	27.1	18.1
Other (income) expense, net	(0.3)	2.5
(Loss) income before income taxes	(24.5)	2.4
Provision for income taxes	10.7	8.7
Net loss	(35.2)	(6.3)
Comprehensive (loss) income	$ (25.6)	$ 16.6

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Operating activities
Net loss	$ (35.2)	$ (6.3)
Depreciation and amortization	25.7	26.3
Provision for deferred income taxes	6.1	3.3
Stock-based compensation expense	0.6	1.7
Unrealized losses (gains) on derivative financial instruments	7.8	(9.2)
Amortization of debt issuance costs	0.8	1.6
Other	1	0
Change in accounts receivable	(50.4)	(55.9)
Change in inventories	(66.9)	5.1
Change in other assets	(0.6)	4.3
Change in accounts payable	43.8	46.1
Change in accrued liabilities	28.7	(5.8)
Net cash (used) provided by operating activities	(38.6)	11.2
Investing activities
Payments for property, plant and equipment	(62.6)	(122)
Other	(0.4)	(0.1)
Net cash used by investing activities	(63)	(122.1)
Financing activities
Proceeds from revolving credit facilities	159.5	110
Payments on revolving credit facilities	(294.5)	(0.2)
Proceeds from senior secured notes, inclusive of premiums	263.8	0
Net payments on other long-term debt	(2.3)	(0.3)
Debt issuance costs	(1.8)	(0.4)
Other	(1.2)	(0.4)
Net cash provided by financing activities	123.5	108.7
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0.6	1.9
Net increase (decrease) in cash, cash equivalents and restricted cash	22.5	(0.3)
Cash, cash equivalents and restricted cash at beginning of period	55.6	62.2
Cash, cash equivalents and restricted cash at end of period	78.1	61.9
Cash and cash equivalents	74.6	61.9
Cash, cash equivalents and restricted cash	$ 55.6	$ 62.2

Basis Of Presentation and Recen

Basis Of Presentation and Recent Accounting Pronouncements	3 Months Ended
Basis Of Presentation and Recent Accounting Pronouncements	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis Of Presentation and Recent Accounting Pronouncements	BASIS OF PRESENTATION AND RECENT ACCOUNTING PRONOUNCEMENTS Basis of Presentation The accompanying unaudited Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. The operating results for interim periods contained herein are not necessarily indicative of the results that may be expected for any other interim period or for the full year. The accompanying Consolidated Financial Statements include the accounts of Aleris Corporation and all of its subsidiaries (collectively, except where the context otherwise requires, referred to as “Aleris,” “we,” “us,” “our,” “Company” or similar terms). Aleris Corporation is a holding company and currently conducts its business and operations through its direct wholly owned subsidiary, Aleris International, Inc. and its consolidated subsidiaries. Aleris International, Inc. is referred to herein as “Aleris International.” Recent Accounting Pronouncements In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” (“ASU 2017-07”). This guidance requires the presentation of all components of net periodic benefit cost other than service costs outside of operating income. Only the service cost component will be included in operating income and eligible for capitalization in assets. The guidance is effective for the Company for fiscal years beginning after December 15, 2017, and will be applied retrospectively. We are currently evaluating the impact the application of ASU 2017-07 will have on the Company’s consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, “Restricted Cash” (“ASU 2016-18”). This guidance requires companies to show the changes in the total cash, cash equivalents and restricted cash in the statement of cash flows. We adopted ASU 2016-18 in the first quarter of 2017. The adoption of this guidance resulted in the updated presentation of restricted cash in our current period Consolidated Statements of Cash Flows. As there was no restricted cash in the prior year, the adoption of this guidance had no affect on the prior year presentation of cash flows. In October 2016, the FASB issued ASU No. 2016-16, “Intra-Entity Transfers of Assets Other Than Inventory” (“ASU 2016-16”). This guidance requires companies to account for the income tax effects of intercompany transfers of assets other than inventory when the transfer occurs. The income tax effects of intercompany inventory transactions will continue to be deferred. We early adopted ASU 2016-16 in the first quarter of 2017. The impact of adopting this guidance on the Company’s consolidated financial statements resulted in credits to prepaid expenses and other current assets and other comprehensive income of approximately $8.2 and $0.1 , respectively, and debits to deferred income tax assets and retained earnings of approximately $3.6 and $4.7 , respectively. In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation-Improvements to Employee Share-Based Payment Accounting” (“ASU 2016-09”). This guidance makes several modifications to the accounting for stock-based compensation, including forfeitures, employer tax withholding on stock-based compensation and the financial statement presentation of excess tax benefits or deficiencies. ASU 2016-09 also clarifies the statement of cash flows presentation for certain components of stock-based awards. We adopted ASU 2016-09 in the first quarter of 2017. The tax effects associated with stock-based compensation are now recorded through the income statement. Additionally, forfeitures will now be recognized as they occur. Prior periods have not been adjusted. In February 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”). This guidance requires lessees to put most leases on their balance sheets but recognize expense on the income statement in a manner similar to current guidance. The guidance is effective for the Company for fiscal years beginning after December 15, 2018, and a modified retrospective approach is required for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. We are currently evaluating the impact the application of ASU 2016-02 will have on the Company’s consolidated financial statements. We expect that the adoption will result in an increase to our long-term assets and long-term liabilities as a result of substantially all operating leases existing as of the adoption date being capitalized along with the associated obligations. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“ASU 2014-09”), which was the result of a joint project by the FASB and International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and International Financial Reporting Standards. Subsequent accounting standard updates have been issued which amend and/or clarify the application of ASU 2014-09. The issuance of a comprehensive and converged standard on revenue recognition is expected to enable financial statement users to better understand and consistently analyze an entity’s revenue across industries, transactions and geographies. The standard will require additional disclosures to help financial statement users better understand the nature, amount, timing, and potential uncertainty of the revenue that is recognized. ASU 2014-09 will be effective for the Company on January 1, 2018, and will require either retrospective application to each prior reporting period presented or retrospective application with the cumulative effect of initially applying the standard recognized at the date of adoption (the “modified retrospective approach”). We are evaluating the impact this guidance will have on the Company’s consolidated financial statements. We expect to adopt this standard using the modified retrospective approach and anticipate that the adoption will result in an increase to the revenue disclosures in our financial statements.

Inventories

Inventories	3 Months Ended
Inventories	Mar. 31, 2017
Inventory Disclosure [Abstract]
Inventories	INVENTORIES The components of our “Inventories” as of March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 Raw materials $ 186.4 $ 181.7 Work in process 233.9 195.4 Finished goods 161.6 134.0 Supplies 28.3 27.8 Total inventories $ 610.2 $ 538.9

Long-Term Debt

Long-Term Debt	3 Months Ended
Long-Term Debt	Mar. 31, 2017
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT Our debt as of March 31, 2017 and December 31, 2016 is summarized as follows: March 31, 2017 December 31, 2016 2015 ABL Facility $ 120.7 $ 255.3 7 7/8% Senior Notes due 2020, net of discount and deferred issuance costs of $4.2 and $4.5 at March 31, 2017 and December 31, 2016, respectively 435.8 435.5 9 1/2% Senior Secured Notes due 2021, inclusive of net premiums and deferred issuance costs of $1.0 at March 31, 2017 and net of discount and deferred issuance costs of $11.6 at December 31, 2016 801.0 538.4 Exchangeable Notes, net of discount of $0.4 at March 31, 2017 and December 31, 2016 44.4 44.4 Zhenjiang Term Loans, net of discount of $0.5 at March 31, 2017 and December 31, 2016 163.8 164.5 Zhenjiang Revolver, net of discount of $0.1 at March 31, 2017 and December 31, 2016 21.9 22.0 Other 5.7 6.1 Total debt 1,593.3 1,466.2 Less: Current portion of long-term debt 28.5 27.7 Total long-term debt $ 1,564.8 $ 1,438.5 9 ½ % Senior Secured Notes due 2021 On February 14, 2017, Aleris International issued an additional $250.0 aggregate principal amount of its 9 ½ % Senior Secured Notes due 2021. The Company initially issued $550.0 aggregate principal amount of 9 ½ % Senior Secured Notes due 2021 on April 4, 2016, which remain outstanding. The additional notes were issued under the indenture governing the previously issued 9 ½ % Senior Secured Notes. The Company received net proceeds of approximately $263.8 , after deducting the initial purchasers’ discount, from the issuance of the additional notes. Theses proceeds are being used for general corporate purposes, which may include working capital and/or capital expenditures.

Commitments And Contingencies

Commitments And Contingencies	3 Months Ended
Commitments And Contingencies	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Environmental Proceedings Our operations are subject to environmental laws and regulations governing air emissions, wastewater discharges, the handling, storage, disposal and remediation of hazardous substances and wastes and employee health and safety. These laws can impose joint and several liabilities for releases or threatened releases of hazardous substances upon statutorily defined parties, including us, regardless of fault or the lawfulness of the original activity or disposal. Given the changing nature of environmental legal requirements, we may be required, from time to time, to take environmental control measures at some of our facilities to meet future requirements. We have been named as a potentially responsible party in certain proceedings initiated pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act and similar state statutes and may be named a potentially responsible party in other similar proceedings in the future. It is not anticipated that the costs incurred in connection with the presently pending proceedings will, individually or in the aggregate, have a material adverse effect on our financial position, results of operations or cash flows. We are performing operations and maintenance at two Superfund sites for matters arising out of past waste disposal activity associated with closed facilities. We are also under orders to perform environmental remediation by agencies in four states and one non-U.S. country at seven sites. Our reserves for environmental remediation liabilities totaled $23.7 and $23.8 at March 31, 2017 and December 31, 2016 , respectively, and have been classified as “Other long-term liabilities” and “Accrued liabilities” in the Consolidated Balance Sheet. Of the environmental liabilities recorded at March 31, 2017 and December 31, 2016 , $11.4 and $11.5 , respectively, are subject to indemnification by third parties. In addition to environmental liabilities, we have recorded asset retirement obligations associated with legal requirements related to the retirement of certain assets. Our total asset retirement obligations were $4.7 at March 31, 2017 and December 31, 2016 . The amounts represent the most probable costs of remedial actions. We estimate the costs related to currently identified remedial actions will be paid out primarily over the next 10 years . Legal Proceedings We are party to routine litigation and proceedings as part of the ordinary course of business and do not believe that the outcome of any existing proceedings would have a material adverse effect on our financial position, results of operations or cash flows. We have established accruals for those loss contingencies, including litigation and environmental contingencies, for which it has been determined that a loss is probable; none of such loss contingencies is material. For those loss contingencies, including litigation and environmental contingencies, which have been determined to be reasonably possible, an estimate of the possible loss or range of loss cannot be determined because the claims, amount claimed, facts or legal status are not sufficiently developed or advanced in order to make such a determination. While we cannot estimate the loss or range of loss at this time, we do not believe that the outcome of any of these existing proceedings would be material to our financial position, results of operations or cash flows.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
Stockholders' Equity	Mar. 31, 2017
Stockholders' Equity Note [Abstract]
Stockholders' Equity and Redeemable Noncontrolling Interest	STOCKHOLDERS ’ EQUITY The following table summarizes the activity within stockholders’ equity for the three months ended March 31, 2017 : Total Equity Total equity at January 1, 2017 $ 216.6 Net loss (35.2 ) Other comprehensive income 9.6 Stock-based compensation activity (0.4 ) Adoption of new accounting standards (4.7 ) Total equity at March 31, 2017 $ 185.9 The following table shows changes in the number of our issued and outstanding shares of common stock: Outstanding shares of common stock Balance at January 1, 2017 31,904,250 Issuance associated with vested restricted stock units 85,462 Balance at March 31, 2017 31,989,712

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	3 Months Ended
Accumulated Other Comprehensive Loss	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	ACCUMULATED OTHER COMPREHENSIVE LOSS The following table summarizes the activity within accumulated other comprehensive loss for the three months ended March 31, 2017 : Currency translation Pension and other postretirement Total Balance at January 1, 2017 $ (150.9 ) $ (72.6 ) $ (223.5 ) Current period currency translation adjustments 9.4 (0.7 ) 8.7 Amortization of net actuarial losses and prior service costs, net of tax — 0.9 0.9 Balance at March 31, 2017 $ (141.5 ) $ (72.4 ) $ (213.9 ) A summary of reclassifications out of accumulated other comprehensive loss for the three months ended March 31, 2017 is provided below: Description of reclassifications out of accumulated other comprehensive loss Amount reclassified Amortization of net actuarial losses and prior service costs $ (1.1 ) (a) Deferred tax benefit on pension and other postretirement liability adjustments 0.2 Losses reclassified into earnings, net of tax $ (0.9 ) (a) This component of accumulated other comprehensive loss is included in the computation of net periodic benefit expense and net postretirement benefit expense (see Note 10, “Employee Benefit Plans,” for additional detail).

Segment Information

Segment Information	3 Months Ended
Segment Information	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION We report three operating segments based on the organizational structure that is used by the chief operating decision maker to evaluate performance, make decisions on resource allocation and for which discrete financial information is available. The Company’s operating segments are North America, Europe and Asia Pacific. Measurement of Segment Income or Loss and Segment Assets The accounting policies of the reportable segments are the same as those described in the summary of significant accounting policies in the Consolidated Financial Statements for the year ended December 31, 2016 . Our measure of profitability for our operating segments is referred to as segment income and loss. Segment income and loss includes gross profits, segment specific realized gains and losses on derivative financial instruments, segment specific other income and expense, segment specific selling, general and administrative (“SG&A”) expense and an allocation of certain functional SG&A expenses. Segment income and loss excludes provisions for and benefits from income taxes, restructuring items, interest, depreciation and amortization, unrealized and certain realized gains and losses on derivative financial instruments, corporate general and administrative costs, start-up costs, gains and losses on asset sales, currency exchange gains and losses on debt and certain other gains and losses. Intra-entity sales and transfers are recorded at market value. Consolidated cash, restricted cash, net capitalized debt costs, deferred tax assets and assets related to our headquarters offices are not allocated to the segments. Reportable Segment Information The following table shows our revenues and segment income for the periods presented in our Consolidated Statements of Comprehensive (Loss) Income : Three months ended March 31, 2017 North America Europe Asia Pacific Intra-entity Revenues Total Revenues to external customers $ 348.5 $ 302.6 $ 23.1 $ 674.2 Intra-entity revenues 3.1 6.4 1.1 $ (10.6 ) — Total revenues $ 351.6 $ 309.0 $ 24.2 $ (10.6 ) $ 674.2 Segment income $ 24.2 $ 38.0 $ 1.4 $ 63.6 Three months ended March 31, 2016 North America Europe Asia Pacific Intra-entity Revenues Total Revenues to external customers $ 333.9 $ 309.1 $ 19.5 $ 662.5 Intra-entity revenues 0.2 3.6 1.8 $ (5.6 ) — Total revenues $ 334.1 $ 312.7 $ 21.3 $ (5.6 ) $ 662.5 Segment income $ 24.2 $ 32.9 $ 0.9 $ 58.0 The following table reconciles total segment income to “ (Loss) income before income taxes ” as reported in our Consolidated Statements of Comprehensive (Loss) Income : For the three months ended March 31, 2017 March 31, 2016 Total segment income $ 63.6 $ 58.0 Unallocated amounts: Depreciation and amortization (25.7 ) (26.3 ) Other corporate general and administrative expenses (12.4 ) (13.1 ) Restructuring charges (0.4 ) (0.8 ) Interest expense, net (27.1 ) (18.1 ) Unallocated (losses) gains on derivative financial instruments (7.7 ) 9.2 Unallocated currency exchange losses (0.1 ) (0.1 ) Start-up costs (14.5 ) (6.3 ) Other expense, net (0.2 ) (0.1 ) (Loss) income before income taxes $ (24.5 ) $ 2.4 The following table shows our reportable segment assets as of March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 Assets North America $ 1,280.0 $ 1,180.2 Europe 697.2 645.3 Asia Pacific 354.8 358.6 Unallocated assets 231.7 205.8 Total consolidated assets $ 2,563.7 $ 2,389.9

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
Stock-Based Compensation	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION On June 1, 2010, the Board of Directors of Aleris Corporation approved the Aleris Corporation 2010 Equity Incentive Plan, which has been amended from time to time (the “2010 Equity Plan”). Stock options, restricted stock units and restricted shares have been granted under the 2010 Equity Plan to certain members of management of the Company and directors. All stock options granted have a life not to exceed ten years and generally vest over a period not to exceed four years. Shares of common stock are issued upon stock option exercises from available shares. The restricted stock units also vest over a period not to exceed four years. A portion of the stock options, as well as a portion of the restricted stock units, may vest upon a change in control event should the event occur prior to full vesting of these awards, depending on the amount of vesting that has already occurred at the time of the event in comparison to the change in our largest stockholders’ overall level of beneficial ownership that results from the event. During the three months ended March 31, 2017 , no stock options or restricted stock units were granted and 21,291 stock options were forfeited. We recorded stock-based compensation expense of $0.6 and $1.7 for the three months ended March 31, 2017 and 2016 , respectively.

Income Taxes

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Our effective tax rates were (43.2)% and 365.4% for the three months ended March 31, 2017 and 2016 , respectively. The effective tax rates for the three months ended March 31, 2017 and 2016 differed from the federal statutory rate applied to income and losses before income taxes primarily as a result of the mix of income, losses and tax rates between tax jurisdictions and valuation allowances. We have valuation allowances recorded to reduce certain deferred tax assets to amounts that are more likely than not to be realized. The valuation allowances relate to the potential inability to realize our deferred tax assets associated with amortization and net operating loss carryforwards in the U.S. and net operating loss carryforwards in non-U.S. jurisdictions. We intend to maintain our valuation allowances until sufficient positive evidence exists (such as cumulative positive earnings and estimated future taxable income) to support their reversal. As of March 31, 2017 , we had $2.4 of unrecognized tax benefits. The majority of the gross unrecognized tax benefits, if recognized, would affect the annual effective tax rate. We recognize interest and penalties related to uncertain tax positions within “Provision for income taxes” in the Consolidated Statements of Comprehensive (Loss) Income . As of March 31, 2017 , we had approximately $0.7 of accrued interest related to uncertain tax positions. The 2009 through 2016 tax years remain open to examination. During the fourth quarter of 2013, a non-U.S. taxing jurisdiction commenced an examination of our tax returns for the tax years ended December 31, 2012, 2011, 2010 and 2009 that is anticipated to be completed within six months of the reporting date.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
Employee Benefit Plans	Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Defined Benefit Pension Plans The components of the net periodic benefit expense are as follows: U.S. pension benefits For the three months ended March 31, 2017 March 31, 2016 Service cost $ 1.0 $ 0.9 Interest cost 1.4 1.5 Amortization of net actuarial losses 0.5 0.5 Amortization of prior service cost 0.1 0.1 Expected return on plan assets (2.6 ) (2.5 ) Net periodic benefit expense $ 0.4 $ 0.5 Non U.S. pension benefits For the three months ended March 31, 2017 March 31, 2016 Service cost $ 0.9 $ 0.5 Interest cost 0.4 0.5 Amortization of net actuarial losses 0.7 0.4 Net periodic benefit expense $ 2.0 $ 1.4 Other Postretirement Benefit Plans The components of net postretirement benefit expense are as follows: For the three months ended March 31, 2017 March 31, 2016 Interest cost $ 0.3 $ 0.3 Amortization of net actuarial gains (0.1 ) — Net postretirement benefit expense $ 0.2 $ 0.3

Derivative And Other Financial

Derivative And Other Financial Instruments	3 Months Ended
Derivative And Other Financial Instruments	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative and Other Financial Instruments	DERIVATIVE AND OTHER FINANCIAL INSTRUMENTS We use forward contracts and options, as well as contractual price escalators, to reduce the risks associated with our metal, natural gas and other supply requirements, as well as fuel costs and certain currency exposures. Generally, we enter into master netting arrangements with our counterparties and offset net derivative positions with the same counterparties against amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral under those arrangements in our Consolidated Balance Sheet. For classification purposes, we record the net fair value of each type of derivative position that is expected to settle in less than one year with each counterparty as a net current asset or liability and each type of long-term position as a net long-term asset or liability. There was no was cash collateral posted at March 31, 2017 or December 31, 2016 . The amounts shown in the table below represent the gross amounts of recognized assets and liabilities, the amounts offset in the Consolidated Balance Sheet and the net amounts of assets and liabilities presented therein. As of March 31, 2017 and December 31, 2016 , there were no amounts subject to an enforceable master netting arrangement or similar agreement that have not been offset in the Consolidated Balance Sheet. Fair Value of Derivatives as of March 31, 2017 December 31, 2016 Derivatives by Type Asset Liability Asset Liability Metal $ 20.0 $ (31.3 ) $ 8.9 $ (12.3 ) Energy 0.1 (0.1 ) 0.7 — Currency 0.1 (1.6 ) — (2.3 ) Total 20.2 (33.0 ) 9.6 (14.6 ) Effect of counterparty netting (16.9 ) 16.9 (6.6 ) 6.6 Net derivatives as classified in the balance sheet $ 3.3 $ (16.1 ) $ 3.0 $ (8.0 ) The fair value of our derivative financial instruments at March 31, 2017 and December 31, 2016 are recorded in the Consolidated Balance Sheet as follows: Asset Derivatives Balance Sheet Location March 31, 2017 December 31, 2016 Metal Prepaid expenses and other current assets $ 0.3 $ 2.3 Other long-term assets 3.0 — Energy Prepaid expenses and other current assets — 0.7 Total $ 3.3 $ 3.0 Liability Derivatives Balance Sheet Location March 31, 2017 December 31, 2016 Metal Accrued liabilities $ 14.6 $ 5.1 Other long-term liabilities — 0.6 Currency Accrued liabilities 1.5 1.8 Other long-term liabilities — 0.5 Total $ 16.1 $ 8.0 Both realized and unrealized gains and losses on derivative financial instruments are included within “ Losses (gains) on derivative financial instruments ” in the Consolidated Statements of Comprehensive (Loss) Income . Realized losses on derivative financial instruments totaled the following: For the three months ended March 31, 2017 March 31, 2016 Metal $ 19.5 $ 7.3 Energy 0.4 0.6 Currency 0.5 0.3 Metal Hedging The selling prices of the majority of the orders for our products are established at the time of order entry or, for certain customers, under long-term contracts. As the related raw materials used to produce these orders are purchased several months or years after the selling prices are fixed, margins are subject to the risk of changes in the purchase price of the raw materials used for these fixed price sales. In order to manage this transactional exposure, future, swaps or forward purchase contracts are purchased at the time the selling prices are fixed. As metal is purchased to fill these fixed price sales orders, future, swaps or forward contracts are then sold. We also maintain a significant amount of inventory on-hand to meet anticipated and unpriced future sales. In order to preserve the value of this inventory, future or forward contracts are sold at the time inventory is purchased. As sales orders are priced, future or forward contracts are purchased. These derivatives generally settle within three months. We can also use call option contracts, which function in a manner similar to the natural gas call option contracts discussed below, and put option contracts for managing metal price exposures. Option contracts require the payment of a premium which is recorded as a realized loss upon settlement or expiration of the option contract. Upon settlement of a put option contract, we receive cash and recognize a related gain if the closing price is less than the strike price of the put option. If the put option strike price is less than the closing price, no amount is paid and the option expires. As of March 31, 2017 and December 31, 2016 , we had 0.1 million and 0.2 million metric tons of metal buy and sell derivative contracts, respectively. Energy Hedging To manage our price exposure for natural gas purchases, we fix the future price of a portion of our natural gas requirements by entering into financial hedge contracts. Under these contracts, payments are made or received based on the differential between the monthly closing price on the New York Mercantile Exchange (“NYMEX”) and the contractual hedge price. We can also use a combination of call option contracts and put option contracts for managing the exposure to increasing natural gas prices while maintaining our ability to benefit from declining prices. Upon settlement of call option contracts, we receive cash and recognize a related gain if the NYMEX closing price exceeds the strike price of the call option. If the call option strike price exceeds the NYMEX closing price, no amount is received and the option expires unexercised. Upon settlement of a put option contract, we pay cash and recognize a related loss if the NYMEX closing price is lower than the strike price of the put option. If the put option strike price is less than the NYMEX closing price, no amount is paid and the option expires unexercised. Option contracts require the payment of a premium which is recorded as a realized loss upon settlement or expiration of the option contract. Natural gas cost can also be managed through the use of cost escalators included in some of our long-term supply contracts with customers, which limits exposure to natural gas price risk. As of March 31, 2017 and December 31, 2016 , we had 1.8 trillion and 2.1 trillion of British thermal unit forward buy contracts, respectively. We use independent freight carriers to deliver our products. As part of the total freight charge, these carriers include a per mile diesel surcharge based on the Department of Energy, Energy Information Administration’s (“DOE”) Weekly Retail Automotive Diesel National Average Price. From time to time we may enter into over-the-counter DOE diesel fuel swaps with financial counterparties to mitigate the impact of the volatility of diesel fuel prices on our freight costs. Under these swap agreements, we pay a fixed price per gallon of diesel fuel determined at the time the agreements were executed and receive a floating rate payment that is determined on a monthly basis based on the average price of the DOE Diesel Fuel Index during the applicable month. The swaps are designed to offset increases or decreases in fuel surcharges that we pay to our carriers. All swaps are financially settled. There is no possibility of physical settlement. As of March 31, 2017 and December 31, 2016 we had no diesel swap contracts. Currency Hedging Our aerospace and heat exchanger businesses expose the U.S. dollar operating results of our European operations to fluctuations in the euro as the sales contracts are generally in U.S. dollars while the costs of production are in euros. In order to mitigate the risk that fluctuations in the euro may have on our business, we have entered into forward currency contracts. As of March 31, 2017 and December 31, 2016 , we had euro forward contracts covering a notional amount of €38.5 million and €34.6 million , respectively. Credit Risk We are exposed to losses in the event of non-performance by the counterparties to the derivative financial instruments discussed above; however, we do not anticipate any non-performance by the counterparties. The counterparties are evaluated for creditworthiness and risk assessment prior to initiating trading activities with the brokers and periodically throughout each year while actively trading. Recurring Fair Value Measurements Derivative contracts are recorded at fair value using quoted market prices and significant other observable inputs. Fair value is defined by FASB Accounting Standards Codification 820, “Fair Value Measurements and Disclosures,” as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The fair value hierarchy distinguishes between (1) market participant assumptions developed based on market data obtained from independent sources (observable inputs) and (2) an entity’s own assumptions about market participant assumptions developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are described below: Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates); and inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3—Inputs that are both significant to the fair value measurement and unobservable. We endeavor to use the best available information in measuring fair value. Where appropriate, valuations are adjusted for various factors such as liquidity, bid/offer spreads, and credit considerations. Such adjustments are generally based on available market evidence and unobservable inputs. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. As of March 31, 2017 and December 31, 2016 , all of our derivative assets and liabilities represent Level 2 fair value measurements. Other Financial Instruments The carrying amount, fair values and level in the fair value hierarchy of our other financial instruments at March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Level in the Fair Value Hierarchy Carrying Amount Fair Value Level in the Fair Value Hierarchy Cash and cash equivalents $ 74.6 $ 74.6 Level 1 $ 55.6 $ 55.6 Level 1 Restricted cash 3.5 3.5 Level 1 — — N/A Receivables held in escrow 17.0 20.6 Level 2 17.0 20.6 Level 2 2015 ABL Facility 120.7 120.7 Level 2 255.3 255.3 N/A 7 7 / 8 % Senior Notes 435.8 431.1 Level 1 435.5 441.7 Level 1 9 ½ % Senior Secured Notes 801.0 862.0 Level 1 538.4 594.0 Level 1 Exchangeable Notes 44.4 81.4 Level 3 44.4 81.4 Level 3 Zhenjiang Term Loans 163.8 164.3 Level 3 164.5 165.0 Level 3 Zhenjiang Revolver 21.9 22.0 Level 3 22.0 22.1 Level 3 The receivables held in escrow include shares of Real Industry, Inc.’s Series B non-participating preferred stock issued to the Company in connection with the 2015 sale of our former North American and European recycling and specification alloys businesses and which have been held in escrow to secure our indemnification obligations under the sale agreement. The fair value was estimated using a lattice model based on the expected time to maturity, cash flows of the preferred stock and an estimated yield using available market data. The principal amount of the 2015 ABL Facility approximates fair value because the interest rate paid is variable and there have been no significant changes in the credit risk of Aleris International subsequent to the borrowings. The fair value of Aleris International’s exchangeable notes was estimated using a binomial lattice pricing model based on the fair value of our common stock, a risk-free interest rate of 1.5% as of March 31, 2017 and 1.6% as of December 31, 2016 , respectively and expected equity volatility of 40% as of March 31, 2017 and 45% as of December 31, 2016 , respectively. Expected equity volatility was determined based on historical stock prices and implied and stated volatilities of our peer companies. The fair values of the 7 7 / 8 % Senior Notes due 2020 (the “7 7 / 8 % Senior Notes”) and 9 ½ % Senior Secured Notes were estimated using market quotations. The principal amount of the Zhenjiang Term Loans and Zhenjiang Revolver approximates fair value because the interest rate paid is variable, is set for periods of six months or less and there have been no significant changes in the credit risk of Aleris Zhenjiang subsequent to the inception of the China Loan Facility.

Potential Acquisition Of Aleris

Potential Acquisition Of Aleris Corporation	3 Months Ended
Potential Acquisition Of Aleris Corporation	Mar. 31, 2017
Business Combinations [Abstract]
Potential Acquisition Of Aleris Corporation	POTENTIAL ACQUISITION OF ALERIS CORPORATION On August 29, 2016, we entered into a definitive agreement to be acquired by Zhongwang USA LLC (“Zhongwang USA”) (the “Merger”). Under the terms of the Merger, Zhongwang USA has agreed to pay approximately $1,110.0 in cash, subject to adjustment, for the equity of Aleris Corporation and will assume certain of the Company’s outstanding indebtedness. The Merger was unanimously approved by the Board of Directors of Aleris Corporation and is targeted to close in the second quarter of 2017, subject to customary regulatory approvals and closing conditions. The Merger is not subject to a financing condition. There can be no assurance that the Merger will be consummated at all or that it will close in the second quarter of 2017.

Condensed Consolidating Financi

Condensed Consolidating Financial Statements	3 Months Ended
Condensed Consolidating Financial Statements	Mar. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Financial Statements	CONDENSED CONSOLIDATING FINANCIAL STATEMENTS Aleris Corporation, the direct parent of Aleris International, and certain of its subsidiaries (collectively, the “Guarantor Subsidiaries”) are guarantors of the indebtedness under the 7 7 / 8 % Senior Notes. Aleris Corporation and each of the Guarantor Subsidiaries have fully and unconditionally guaranteed (subject, in the case of the Guarantor Subsidiaries, to customary release provisions as described below), on a joint and several basis, to pay principal and interest related to the 7 7 / 8 % Senior Notes and Aleris International and each of the Guarantor Subsidiaries are directly or indirectly 100% owned subsidiaries of Aleris Corporation. For purposes of complying with the reporting requirements of Aleris International and the Guarantor Subsidiaries, presented below are condensed consolidating financial statements of Aleris Corporation, Aleris International, the Guarantor Subsidiaries, and those other subsidiaries of Aleris Corporation that are not guaranteeing the indebtedness under the 7 7 / 8 % Senior Notes (the “Non-Guarantor Subsidiaries”). Aleris Corporation and the Guarantor Subsidiaries are also guarantors under the 9 ½ % Senior Secured Notes. The condensed consolidating balance sheets are presented as of March 31, 2017 and December 31, 2016 . The condensed consolidating statements of comprehensive income (loss) and the condensed consolidating statements of cash flows are presented for the three months ended March 31, 2017 and 2016 . The guarantee of a Guarantor Subsidiary will be automatically and unconditionally released and discharged in the event of: ▪ any sale of the Guarantor Subsidiary or of all or substantially all of its assets and if applicable, the release or discharge from its guarantee of, and all pledges and security granted by it in connection with, the 2015 ABL Facility; ▪ a Guarantor Subsidiary being designated as an “unrestricted subsidiary” in accordance with the indentures governing the applicable Senior Notes; ▪ the release or discharge of a Guarantor Subsidiary from its guarantee under the 2015 ABL Facility or other indebtedness that resulted in the obligation of the Guarantor Subsidiary under the indentures governing the applicable Senior Notes; and ▪ the requirements for legal defeasance or covenant defeasance or discharge of the indentures governing the applicable Senior Notes having been satisfied. Upon the completion of the sale of the recycling and specification alloys business on February 27, 2015, the guarantees of 7 7 / 8 % Senior Notes of the Guarantor Subsidiaries that were sold were automatically and unconditionally released. As of March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets Cash and cash equivalents $ — $ 42.7 $ — $ 34.2 $ (2.3 ) $ 74.6 Accounts receivable, net — — 107.9 163.4 — 271.3 Inventories — — 286.1 324.1 — 610.2 Prepaid expenses and other current assets — 0.6 14.6 21.4 — 36.6 Intercompany receivables — 208.0 64.7 159.6 (432.3 ) — Total Current Assets — 251.3 473.3 702.7 (434.6 ) 992.7 Property, plant and equipment, net — — 848.9 526.3 — 1,375.2 Intangible assets, net — — 20.4 15.9 — 36.3 Deferred income taxes — — — 91.9 — 91.9 Other long-term assets — 11.7 6.1 49.8 — 67.6 Investments in subsidiaries 187.8 1,457.4 (3.1 ) — (1,642.1 ) — Total Assets $ 187.8 $ 1,720.4 $ 1,345.6 $ 1,386.6 $ (2,076.7 ) $ 2,563.7 LIABILITIES AND STOCKHOLDERS’ EQUITY Current Liabilities Accounts payable $ — $ 2.2 $ 155.6 $ 138.6 $ (2.3 ) $ 294.1 Accrued liabilities — 53.3 90.5 80.8 — 224.6 Current portion of long-term debt — — 0.4 28.1 — 28.5 Intercompany payables 1.9 195.9 218.2 16.3 (432.3 ) — Total Current Liabilities 1.9 251.4 464.7 263.8 (434.6 ) 547.2 Long-term debt — 1,281.2 0.5 283.1 — 1,564.8 Deferred income taxes — — 0.2 9.0 — 9.2 Accrued pension benefits — — 43.7 116.1 — 159.8 Accrued postretirement benefits — — 33.6 — — 33.6 Other long-term liabilities — — 36.7 26.5 — 63.2 Total Long-Term Liabilities — 1,281.2 114.7 434.7 — 1,830.6 Total equity 185.9 187.8 766.2 688.1 (1,642.1 ) 185.9 Total Liabilities and Equity $ 187.8 $ 1,720.4 $ 1,345.6 $ 1,386.6 $ (2,076.7 ) $ 2,563.7 As of December 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets Cash and cash equivalents $ — $ 5.5 $ — $ 53.3 $ (3.2 ) $ 55.6 Accounts receivable, net — — 81.0 137.7 — 218.7 Inventories — — 240.8 298.1 — 538.9 Prepaid expenses and other current assets — — 15.2 18.2 — 33.4 Intercompany receivables — 897.9 296.5 164.2 (1,358.6 ) — Total Current Assets — 903.4 633.5 671.5 (1,361.8 ) 846.6 Property, plant and equipment, net — — 819.1 526.9 — 1,346.0 Intangible assets, net — — 20.9 15.9 — 36.8 Deferred income taxes — — — 88.3 — 88.3 Other long-term assets — 10.8 6.1 55.3 — 72.2 Investments in subsidiaries 217.6 1,089.6 2.8 — (1,310.0 ) — Total Assets $ 217.6 $ 2,003.8 $ 1,482.4 $ 1,357.9 $ (2,671.8 ) $ 2,389.9 LIABILITIES AND STOCKHOLDERS’ EQUITY Current Liabilities Accounts payable $ — $ 1.8 $ 126.1 $ 121.9 $ (3.2 ) $ 246.6 Accrued liabilities — 19.8 109.3 72.3 — 201.4 Current portion of long-term debt — — 0.5 27.2 — 27.7 Intercompany payables 1.0 616.2 719.6 21.8 (1,358.6 ) — Total Current Liabilities 1.0 637.8 955.5 243.2 (1,361.8 ) 475.7 Long-term debt — 1,148.4 0.6 289.5 — 1,438.5 Deferred income taxes — — 0.2 2.6 — 2.8 Accrued pension benefits — — 44.1 114.3 — 158.4 Accrued postretirement benefits — — 34.2 — — 34.2 Other long-term liabilities — — 36.5 27.2 — 63.7 Total Long-Term Liabilities — 1,148.4 115.6 433.6 — 1,697.6 Total equity 216.6 217.6 411.3 681.1 (1,310.0 ) 216.6 Total Liabilities and Equity $ 217.6 $ 2,003.8 $ 1,482.4 $ 1,357.9 $ (2,671.8 ) $ 2,389.9 For the three months ended March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenues $ — $ — $ 349.4 $ 332.1 $ (7.3 ) $ 674.2 Cost of sales — — 324.6 271.8 (7.3 ) 589.1 Gross profit — — 24.8 60.3 — 85.1 Selling, general and administrative expenses — 0.1 32.4 20.7 — 53.2 Restructuring charges — — 0.3 0.1 — 0.4 Losses on derivative financial instruments — — 20.0 8.2 — 28.2 Other operating expense, net — — 1.0 — — 1.0 Operating (loss) income — (0.1 ) (28.9 ) 31.3 — 2.3 Interest expense, net — — 20.7 6.4 — 27.1 Other (income) expense, net — (0.3 ) (1.2 ) 1.2 — (0.3 ) Equity in net loss (earnings) of affiliates 35.2 35.3 (0.2 ) — (70.3 ) — (Loss) income before income taxes (35.2 ) (35.1 ) (48.2 ) 23.7 70.3 (24.5 ) Provision for (benefit from) income taxes — 0.1 (0.1 ) 10.7 — 10.7 Net (loss) income $ (35.2 ) $ (35.2 ) $ (48.1 ) $ 13.0 $ 70.3 $ (35.2 ) Comprehensive (loss) income $ (25.6 ) $ (25.6 ) $ (47.6 ) $ 22.2 $ 51.0 $ (25.6 ) For the three months ended March 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenues $ — $ — $ 334.1 $ 332.1 $ (3.7 ) $ 662.5 Cost of sales — — 306.7 286.0 (3.7 ) 589.0 Gross profit — — 27.4 46.1 — 73.5 Selling, general and administrative expenses — 1.3 28.6 20.4 — 50.3 Restructuring charges — — 0.3 0.5 — 0.8 Losses (gains) on derivative financial instruments — — 1.7 (2.7 ) — (1.0 ) Other operating expense, net — — 0.3 0.1 — 0.4 Operating (loss) income — (1.3 ) (3.5 ) 27.8 — 23.0 Interest expense, net — — 9.8 8.3 — 18.1 Other (income) expense, net — (3.7 ) (1.2 ) 7.4 — 2.5 Equity in net loss (earnings) of affiliates 6.3 8.7 (0.4 ) — (14.6 ) — (Loss) income before income taxes (6.3 ) (6.3 ) (11.7 ) 12.1 14.6 2.4 (Benefit from) provision for income taxes — — (0.2 ) 8.9 — 8.7 Net (loss) income $ (6.3 ) $ (6.3 ) $ (11.5 ) $ 3.2 $ 14.6 $ (6.3 ) Comprehensive income (loss) $ 16.6 $ 16.6 $ (10.5 ) $ 25.2 $ (31.3 ) $ 16.6 For the three months ended March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash provided (used) by operating activities $ 1.1 $ 303.5 $ (355.6 ) $ 11.8 $ 0.6 $ (38.6 ) Investing activities Payments for property, plant and equipment — — (52.7 ) (9.9 ) — (62.6 ) Equity contributions in subsidiaries — (406.6 ) — — 406.6 — Return of investment in subsidiaries — 8.3 5.8 — (14.1 ) — Other — — (0.4 ) — — (0.4 ) Net cash used by investing activities — (398.3 ) (47.3 ) (9.9 ) 392.5 (63.0 ) Financing activities Proceeds from the revolving credit facilities — 55.0 — 104.5 — 159.5 Payments on the revolving credit facilities — (185.0 ) — (109.5 ) — (294.5 ) Proceeds from senior secured notes, inclusive of premiums — 263.8 — — — 263.8 Payments on other long-term debt — — (0.1 ) (2.2 ) — (2.3 ) Debt issuance costs (1.8 ) — — — (1.8 ) Proceeds from intercompany equity contributions — — 402.6 4.0 (406.6 ) — Dividends paid — — — (14.4 ) 14.4 — Other (1.1 ) — 0.4 (0.5 ) — (1.2 ) Net cash (used) provided by financing activities (1.1 ) 132.0 402.9 (18.1 ) (392.2 ) 123.5 Effect of exchange rate differences on cash, cash equivalents and restricted cash — — — 0.6 — 0.6 Net increase (decrease) in cash, cash equivalents and restricted cash — 37.2 — (15.6 ) 0.9 22.5 Cash, cash equivalents and restricted cash at beginning of period — 5.5 — 53.3 (3.2 ) 55.6 Cash, cash equivalents and restricted cash at end of period $ — $ 42.7 $ — $ 37.7 $ (2.3 ) $ 78.1 Cash and cash equivalents $ — $ 42.7 $ — $ 34.2 $ (2.3 ) $ 74.6 Restricted cash (included in Other current assets) — — — 3.5 — 3.5 Cash, cash equivalents and restricted cash $ — $ 42.7 $ — $ 37.7 $ (2.3 ) $ 78.1 For the three months ended March 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash provided (used) by operating activities $ 0.4 $ (115.0 ) $ 100.3 $ 26.0 $ (0.5 ) $ 11.2 Investing activities Payments for property, plant and equipment — — (99.7 ) (22.3 ) — (122.0 ) Return of investments in subsidiaries — 5.0 0.1 — (5.1 ) — Other — — — (0.1 ) — (0.1 ) Net cash provided (used) by investing activities — 5.0 (99.6 ) (22.4 ) (5.1 ) (122.1 ) Financing activities Proceeds from revolving credit facilities — 110.0 — — — 110.0 Payments on revolving credit facilities — — — (0.2 ) — (0.2 ) Net proceeds from (payments on) other long-term debt — 0.1 (0.3 ) (0.1 ) — (0.3 ) Debt issuance costs — (0.4 ) — — — (0.4 ) Dividends paid — — (0.3 ) (5.3 ) 5.6 — Other (0.4 ) 0.3 (0.1 ) (0.2 ) — (0.4 ) Net cash (used) provided by financing activities (0.4 ) 110.0 (0.7 ) (5.8 ) 5.6 108.7 Effect of exchange rate differences on cash, cash equivalents and restricted cash — — — 1.9 — 1.9 Net decrease in cash, cash equivalents and restricted cash — — — (0.3 ) — (0.3 ) Cash, cash equivalents and restricted cash at beginning of period — — — 62.2 — 62.2 Cash, cash equivalents and restricted cash at end of period $ — $ — $ — $ 61.9 $ — $ 61.9

Basis Of Presentation and Rec19

Basis Of Presentation and Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.
New Accounting Pronouncements	Recent Accounting Pronouncements In March 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2017-07, “Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost” (“ASU 2017-07”). This guidance requires the presentation of all components of net periodic benefit cost other than service costs outside of operating income. Only the service cost component will be included in operating income and eligible for capitalization in assets. The guidance is effective for the Company for fiscal years beginning after December 15, 2017, and will be applied retrospectively. We are currently evaluating the impact the application of ASU 2017-07 will have on the Company’s consolidated financial statements. In November 2016, the FASB issued ASU No. 2016-18, “Restricted Cash” (“ASU 2016-18”). This guidance requires companies to show the changes in the total cash, cash equivalents and restricted cash in the statement of cash flows. We adopted ASU 2016-18 in the first quarter of 2017. The adoption of this guidance resulted in the updated presentation of restricted cash in our current period Consolidated Statements of Cash Flows. As there was no restricted cash in the prior year, the adoption of this guidance had no affect on the prior year presentation of cash flows. In October 2016, the FASB issued ASU No. 2016-16, “Intra-Entity Transfers of Assets Other Than Inventory” (“ASU 2016-16”). This guidance requires companies to account for the income tax effects of intercompany transfers of assets other than inventory when the transfer occurs. The income tax effects of intercompany inventory transactions will continue to be deferred. We early adopted ASU 2016-16 in the first quarter of 2017. The impact of adopting this guidance on the Company’s consolidated financial statements resulted in credits to prepaid expenses and other current assets and other comprehensive income of approximately $8.2 and $0.1 , respectively, and debits to deferred income tax assets and retained earnings of approximately $3.6 and $4.7 , respectively. In March 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation-Improvements to Employee Share-Based Payment Accounting” (“ASU 2016-09”). This guidance makes several modifications to the accounting for stock-based compensation, including forfeitures, employer tax withholding on stock-based compensation and the financial statement presentation of excess tax benefits or deficiencies. ASU 2016-09 also clarifies the statement of cash flows presentation for certain components of stock-based awards. We adopted ASU 2016-09 in the first quarter of 2017. The tax effects associated with stock-based compensation are now recorded through the income statement. Additionally, forfeitures will now be recognized as they occur. Prior periods have not been adjusted. In February 2016, the FASB issued ASU 2016-02, “Leases” (“ASU 2016-02”). This guidance requires lessees to put most leases on their balance sheets but recognize expense on the income statement in a manner similar to current guidance. The guidance is effective for the Company for fiscal years beginning after December 15, 2018, and a modified retrospective approach is required for leases that exist or are entered into after the beginning of the earliest comparative period in the financial statements. We are currently evaluating the impact the application of ASU 2016-02 will have on the Company’s consolidated financial statements. We expect that the adoption will result in an increase to our long-term assets and long-term liabilities as a result of substantially all operating leases existing as of the adoption date being capitalized along with the associated obligations. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606)” (“ASU 2014-09”), which was the result of a joint project by the FASB and International Accounting Standards Board to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and International Financial Reporting Standards. Subsequent accounting standard updates have been issued which amend and/or clarify the application of ASU 2014-09. The issuance of a comprehensive and converged standard on revenue recognition is expected to enable financial statement users to better understand and consistently analyze an entity’s revenue across industries, transactions and geographies. The standard will require additional disclosures to help financial statement users better understand the nature, amount, timing, and potential uncertainty of the revenue that is recognized. ASU 2014-09 will be effective for the Company on January 1, 2018, and will require either retrospective application to each prior reporting period presented or retrospective application with the cumulative effect of initially applying the standard recognized at the date of adoption (the “modified retrospective approach”). We are evaluating the impact this guidance will have on the Company’s consolidated financial statements. We expect to adopt this standard using the modified retrospective approach and anticipate that the adoption will result in an increase to the revenue disclosures in our financial statements.

Inventories (Tables)

Inventories (Tables)	3 Months Ended
Inventories (Tables)	Mar. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	The components of our “Inventories” as of March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 Raw materials $ 186.4 $ 181.7 Work in process 233.9 195.4 Finished goods 161.6 134.0 Supplies 28.3 27.8 Total inventories $ 610.2 $ 538.9

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
Long-Term Debt (Tables)	Mar. 31, 2017
Debt Disclosure [Abstract]
Schedule of Debt	Our debt as of March 31, 2017 and December 31, 2016 is summarized as follows: March 31, 2017 December 31, 2016 2015 ABL Facility $ 120.7 $ 255.3 7 7/8% Senior Notes due 2020, net of discount and deferred issuance costs of $4.2 and $4.5 at March 31, 2017 and December 31, 2016, respectively 435.8 435.5 9 1/2% Senior Secured Notes due 2021, inclusive of net premiums and deferred issuance costs of $1.0 at March 31, 2017 and net of discount and deferred issuance costs of $11.6 at December 31, 2016 801.0 538.4 Exchangeable Notes, net of discount of $0.4 at March 31, 2017 and December 31, 2016 44.4 44.4 Zhenjiang Term Loans, net of discount of $0.5 at March 31, 2017 and December 31, 2016 163.8 164.5 Zhenjiang Revolver, net of discount of $0.1 at March 31, 2017 and December 31, 2016 21.9 22.0 Other 5.7 6.1 Total debt 1,593.3 1,466.2 Less: Current portion of long-term debt 28.5 27.7 Total long-term debt $ 1,564.8 $ 1,438.5

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
Stockholders' Equity (Tables)	Mar. 31, 2017
Stockholders' Equity Note [Abstract]
Schedule of Stockholders Equity	The following table summarizes the activity within stockholders’ equity for the three months ended March 31, 2017 : Total Equity Total equity at January 1, 2017 $ 216.6 Net loss (35.2 ) Other comprehensive income 9.6 Stock-based compensation activity (0.4 ) Adoption of new accounting standards (4.7 ) Total equity at March 31, 2017 $ 185.9
Changes in the Number of Outstanding Common Shares	The following table shows changes in the number of our issued and outstanding shares of common stock: Outstanding shares of common stock Balance at January 1, 2017 31,904,250 Issuance associated with vested restricted stock units 85,462 Balance at March 31, 2017 31,989,712

Accumulated Other Comprehensi23

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
Accumulated Other Comprehensive Loss (Tables)	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income	The following table summarizes the activity within accumulated other comprehensive loss for the three months ended March 31, 2017 : Currency translation Pension and other postretirement Total Balance at January 1, 2017 $ (150.9 ) $ (72.6 ) $ (223.5 ) Current period currency translation adjustments 9.4 (0.7 ) 8.7 Amortization of net actuarial losses and prior service costs, net of tax — 0.9 0.9 Balance at March 31, 2017 $ (141.5 ) $ (72.4 ) $ (213.9 )
Schedule of Amounts Recognized in Other Comprehensive Income	A summary of reclassifications out of accumulated other comprehensive loss for the three months ended March 31, 2017 is provided below: Description of reclassifications out of accumulated other comprehensive loss Amount reclassified Amortization of net actuarial losses and prior service costs $ (1.1 ) (a) Deferred tax benefit on pension and other postretirement liability adjustments 0.2 Losses reclassified into earnings, net of tax $ (0.9 ) (a) This component of accumulated other comprehensive loss is included in the computation of net periodic benefit expense and net postretirement benefit expense (see Note 10, “Employee Benefit Plans,” for additional detail).

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
Segment Information (Tables)	Mar. 31, 2017
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following table shows our revenues and segment income for the periods presented in our Consolidated Statements of Comprehensive (Loss) Income : Three months ended March 31, 2017 North America Europe Asia Pacific Intra-entity Revenues Total Revenues to external customers $ 348.5 $ 302.6 $ 23.1 $ 674.2 Intra-entity revenues 3.1 6.4 1.1 $ (10.6 ) — Total revenues $ 351.6 $ 309.0 $ 24.2 $ (10.6 ) $ 674.2 Segment income $ 24.2 $ 38.0 $ 1.4 $ 63.6 Three months ended March 31, 2016 North America Europe Asia Pacific Intra-entity Revenues Total Revenues to external customers $ 333.9 $ 309.1 $ 19.5 $ 662.5 Intra-entity revenues 0.2 3.6 1.8 $ (5.6 ) — Total revenues $ 334.1 $ 312.7 $ 21.3 $ (5.6 ) $ 662.5 Segment income $ 24.2 $ 32.9 $ 0.9 $ 58.0
Schedule of Segment Reporting Information, by Segment	The following table reconciles total segment income to “ (Loss) income before income taxes ” as reported in our Consolidated Statements of Comprehensive (Loss) Income : For the three months ended March 31, 2017 March 31, 2016 Total segment income $ 63.6 $ 58.0 Unallocated amounts: Depreciation and amortization (25.7 ) (26.3 ) Other corporate general and administrative expenses (12.4 ) (13.1 ) Restructuring charges (0.4 ) (0.8 ) Interest expense, net (27.1 ) (18.1 ) Unallocated (losses) gains on derivative financial instruments (7.7 ) 9.2 Unallocated currency exchange losses (0.1 ) (0.1 ) Start-up costs (14.5 ) (6.3 ) Other expense, net (0.2 ) (0.1 ) (Loss) income before income taxes $ (24.5 ) $ 2.4
Reconciliation of Assets from Segment to Consolidated	The following table shows our reportable segment assets as of March 31, 2017 and December 31, 2016 : March 31, 2017 December 31, 2016 Assets North America $ 1,280.0 $ 1,180.2 Europe 697.2 645.3 Asia Pacific 354.8 358.6 Unallocated assets 231.7 205.8 Total consolidated assets $ 2,563.7 $ 2,389.9

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
Employee Benefit Plans (Tables)	Mar. 31, 2017
U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Schedule of Defined Benefit Plans Disclosures	The components of the net periodic benefit expense are as follows: U.S. pension benefits For the three months ended March 31, 2017 March 31, 2016 Service cost $ 1.0 $ 0.9 Interest cost 1.4 1.5 Amortization of net actuarial losses 0.5 0.5 Amortization of prior service cost 0.1 0.1 Expected return on plan assets (2.6 ) (2.5 ) Net periodic benefit expense $ 0.4 $ 0.5
European Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Schedule of Defined Benefit Plans Disclosures	Non U.S. pension benefits For the three months ended March 31, 2017 March 31, 2016 Service cost $ 0.9 $ 0.5 Interest cost 0.4 0.5 Amortization of net actuarial losses 0.7 0.4 Net periodic benefit expense $ 2.0 $ 1.4
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Schedule of Defined Benefit Plans Disclosures	The components of net postretirement benefit expense are as follows: For the three months ended March 31, 2017 March 31, 2016 Interest cost $ 0.3 $ 0.3 Amortization of net actuarial gains (0.1 ) — Net postretirement benefit expense $ 0.2 $ 0.3

Derivative And Other Financia26

Derivative And Other Financial Instruments (Tables)	3 Months Ended
Derivative And Other Financial Instruments (Tables)	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The amounts shown in the table below represent the gross amounts of recognized assets and liabilities, the amounts offset in the Consolidated Balance Sheet and the net amounts of assets and liabilities presented therein. As of March 31, 2017 and December 31, 2016 , there were no amounts subject to an enforceable master netting arrangement or similar agreement that have not been offset in the Consolidated Balance Sheet. Fair Value of Derivatives as of March 31, 2017 December 31, 2016 Derivatives by Type Asset Liability Asset Liability Metal $ 20.0 $ (31.3 ) $ 8.9 $ (12.3 ) Energy 0.1 (0.1 ) 0.7 — Currency 0.1 (1.6 ) — (2.3 ) Total 20.2 (33.0 ) 9.6 (14.6 ) Effect of counterparty netting (16.9 ) 16.9 (6.6 ) 6.6 Net derivatives as classified in the balance sheet $ 3.3 $ (16.1 ) $ 3.0 $ (8.0 )
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	The fair value of our derivative financial instruments at March 31, 2017 and December 31, 2016 are recorded in the Consolidated Balance Sheet as follows: Asset Derivatives Balance Sheet Location March 31, 2017 December 31, 2016 Metal Prepaid expenses and other current assets $ 0.3 $ 2.3 Other long-term assets 3.0 — Energy Prepaid expenses and other current assets — 0.7 Total $ 3.3 $ 3.0 Liability Derivatives Balance Sheet Location March 31, 2017 December 31, 2016 Metal Accrued liabilities $ 14.6 $ 5.1 Other long-term liabilities — 0.6 Currency Accrued liabilities 1.5 1.8 Other long-term liabilities — 0.5 Total $ 16.1 $ 8.0
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance	Realized losses on derivative financial instruments totaled the following: For the three months ended March 31, 2017 March 31, 2016 Metal $ 19.5 $ 7.3 Energy 0.4 0.6 Currency 0.5 0.3
Schedule of Fair Value Measurements, Nonrecurring	The carrying amount, fair values and level in the fair value hierarchy of our other financial instruments at March 31, 2017 and December 31, 2016 are as follows: March 31, 2017 December 31, 2016 Carrying Amount Fair Value Level in the Fair Value Hierarchy Carrying Amount Fair Value Level in the Fair Value Hierarchy Cash and cash equivalents $ 74.6 $ 74.6 Level 1 $ 55.6 $ 55.6 Level 1 Restricted cash 3.5 3.5 Level 1 — — N/A Receivables held in escrow 17.0 20.6 Level 2 17.0 20.6 Level 2 2015 ABL Facility 120.7 120.7 Level 2 255.3 255.3 N/A 7 7 / 8 % Senior Notes 435.8 431.1 Level 1 435.5 441.7 Level 1 9 ½ % Senior Secured Notes 801.0 862.0 Level 1 538.4 594.0 Level 1 Exchangeable Notes 44.4 81.4 Level 3 44.4 81.4 Level 3 Zhenjiang Term Loans 163.8 164.3 Level 3 164.5 165.0 Level 3 Zhenjiang Revolver 21.9 22.0 Level 3 22.0 22.1 Level 3

Condensed Consolidating Finan27

Condensed Consolidating Financial Statements (Tables)	3 Months Ended
Condensed Consolidating Financial Statements (Tables)	Mar. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheet	As of March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets Cash and cash equivalents $ — $ 42.7 $ — $ 34.2 $ (2.3 ) $ 74.6 Accounts receivable, net — — 107.9 163.4 — 271.3 Inventories — — 286.1 324.1 — 610.2 Prepaid expenses and other current assets — 0.6 14.6 21.4 — 36.6 Intercompany receivables — 208.0 64.7 159.6 (432.3 ) — Total Current Assets — 251.3 473.3 702.7 (434.6 ) 992.7 Property, plant and equipment, net — — 848.9 526.3 — 1,375.2 Intangible assets, net — — 20.4 15.9 — 36.3 Deferred income taxes — — — 91.9 — 91.9 Other long-term assets — 11.7 6.1 49.8 — 67.6 Investments in subsidiaries 187.8 1,457.4 (3.1 ) — (1,642.1 ) — Total Assets $ 187.8 $ 1,720.4 $ 1,345.6 $ 1,386.6 $ (2,076.7 ) $ 2,563.7 LIABILITIES AND STOCKHOLDERS’ EQUITY Current Liabilities Accounts payable $ — $ 2.2 $ 155.6 $ 138.6 $ (2.3 ) $ 294.1 Accrued liabilities — 53.3 90.5 80.8 — 224.6 Current portion of long-term debt — — 0.4 28.1 — 28.5 Intercompany payables 1.9 195.9 218.2 16.3 (432.3 ) — Total Current Liabilities 1.9 251.4 464.7 263.8 (434.6 ) 547.2 Long-term debt — 1,281.2 0.5 283.1 — 1,564.8 Deferred income taxes — — 0.2 9.0 — 9.2 Accrued pension benefits — — 43.7 116.1 — 159.8 Accrued postretirement benefits — — 33.6 — — 33.6 Other long-term liabilities — — 36.7 26.5 — 63.2 Total Long-Term Liabilities — 1,281.2 114.7 434.7 — 1,830.6 Total equity 185.9 187.8 766.2 688.1 (1,642.1 ) 185.9 Total Liabilities and Equity $ 187.8 $ 1,720.4 $ 1,345.6 $ 1,386.6 $ (2,076.7 ) $ 2,563.7 As of December 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets Cash and cash equivalents $ — $ 5.5 $ — $ 53.3 $ (3.2 ) $ 55.6 Accounts receivable, net — — 81.0 137.7 — 218.7 Inventories — — 240.8 298.1 — 538.9 Prepaid expenses and other current assets — — 15.2 18.2 — 33.4 Intercompany receivables — 897.9 296.5 164.2 (1,358.6 ) — Total Current Assets — 903.4 633.5 671.5 (1,361.8 ) 846.6 Property, plant and equipment, net — — 819.1 526.9 — 1,346.0 Intangible assets, net — — 20.9 15.9 — 36.8 Deferred income taxes — — — 88.3 — 88.3 Other long-term assets — 10.8 6.1 55.3 — 72.2 Investments in subsidiaries 217.6 1,089.6 2.8 — (1,310.0 ) — Total Assets $ 217.6 $ 2,003.8 $ 1,482.4 $ 1,357.9 $ (2,671.8 ) $ 2,389.9 LIABILITIES AND STOCKHOLDERS’ EQUITY Current Liabilities Accounts payable $ — $ 1.8 $ 126.1 $ 121.9 $ (3.2 ) $ 246.6 Accrued liabilities — 19.8 109.3 72.3 — 201.4 Current portion of long-term debt — — 0.5 27.2 — 27.7 Intercompany payables 1.0 616.2 719.6 21.8 (1,358.6 ) — Total Current Liabilities 1.0 637.8 955.5 243.2 (1,361.8 ) 475.7 Long-term debt — 1,148.4 0.6 289.5 — 1,438.5 Deferred income taxes — — 0.2 2.6 — 2.8 Accrued pension benefits — — 44.1 114.3 — 158.4 Accrued postretirement benefits — — 34.2 — — 34.2 Other long-term liabilities — — 36.5 27.2 — 63.7 Total Long-Term Liabilities — 1,148.4 115.6 433.6 — 1,697.6 Total equity 216.6 217.6 411.3 681.1 (1,310.0 ) 216.6 Total Liabilities and Equity $ 217.6 $ 2,003.8 $ 1,482.4 $ 1,357.9 $ (2,671.8 ) $ 2,389.9
Schedule of Condensed Income Statement	For the three months ended March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenues $ — $ — $ 349.4 $ 332.1 $ (7.3 ) $ 674.2 Cost of sales — — 324.6 271.8 (7.3 ) 589.1 Gross profit — — 24.8 60.3 — 85.1 Selling, general and administrative expenses — 0.1 32.4 20.7 — 53.2 Restructuring charges — — 0.3 0.1 — 0.4 Losses on derivative financial instruments — — 20.0 8.2 — 28.2 Other operating expense, net — — 1.0 — — 1.0 Operating (loss) income — (0.1 ) (28.9 ) 31.3 — 2.3 Interest expense, net — — 20.7 6.4 — 27.1 Other (income) expense, net — (0.3 ) (1.2 ) 1.2 — (0.3 ) Equity in net loss (earnings) of affiliates 35.2 35.3 (0.2 ) — (70.3 ) — (Loss) income before income taxes (35.2 ) (35.1 ) (48.2 ) 23.7 70.3 (24.5 ) Provision for (benefit from) income taxes — 0.1 (0.1 ) 10.7 — 10.7 Net (loss) income $ (35.2 ) $ (35.2 ) $ (48.1 ) $ 13.0 $ 70.3 $ (35.2 ) Comprehensive (loss) income $ (25.6 ) $ (25.6 ) $ (47.6 ) $ 22.2 $ 51.0 $ (25.6 ) For the three months ended March 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Revenues $ — $ — $ 334.1 $ 332.1 $ (3.7 ) $ 662.5 Cost of sales — — 306.7 286.0 (3.7 ) 589.0 Gross profit — — 27.4 46.1 — 73.5 Selling, general and administrative expenses — 1.3 28.6 20.4 — 50.3 Restructuring charges — — 0.3 0.5 — 0.8 Losses (gains) on derivative financial instruments — — 1.7 (2.7 ) — (1.0 ) Other operating expense, net — — 0.3 0.1 — 0.4 Operating (loss) income — (1.3 ) (3.5 ) 27.8 — 23.0 Interest expense, net — — 9.8 8.3 — 18.1 Other (income) expense, net — (3.7 ) (1.2 ) 7.4 — 2.5 Equity in net loss (earnings) of affiliates 6.3 8.7 (0.4 ) — (14.6 ) — (Loss) income before income taxes (6.3 ) (6.3 ) (11.7 ) 12.1 14.6 2.4 (Benefit from) provision for income taxes — — (0.2 ) 8.9 — 8.7 Net (loss) income $ (6.3 ) $ (6.3 ) $ (11.5 ) $ 3.2 $ 14.6 $ (6.3 ) Comprehensive income (loss) $ 16.6 $ 16.6 $ (10.5 ) $ 25.2 $ (31.3 ) $ 16.6
Schedule of Condensed Cash Flow Statement	For the three months ended March 31, 2017 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash provided (used) by operating activities $ 1.1 $ 303.5 $ (355.6 ) $ 11.8 $ 0.6 $ (38.6 ) Investing activities Payments for property, plant and equipment — — (52.7 ) (9.9 ) — (62.6 ) Equity contributions in subsidiaries — (406.6 ) — — 406.6 — Return of investment in subsidiaries — 8.3 5.8 — (14.1 ) — Other — — (0.4 ) — — (0.4 ) Net cash used by investing activities — (398.3 ) (47.3 ) (9.9 ) 392.5 (63.0 ) Financing activities Proceeds from the revolving credit facilities — 55.0 — 104.5 — 159.5 Payments on the revolving credit facilities — (185.0 ) — (109.5 ) — (294.5 ) Proceeds from senior secured notes, inclusive of premiums — 263.8 — — — 263.8 Payments on other long-term debt — — (0.1 ) (2.2 ) — (2.3 ) Debt issuance costs (1.8 ) — — — (1.8 ) Proceeds from intercompany equity contributions — — 402.6 4.0 (406.6 ) — Dividends paid — — — (14.4 ) 14.4 — Other (1.1 ) — 0.4 (0.5 ) — (1.2 ) Net cash (used) provided by financing activities (1.1 ) 132.0 402.9 (18.1 ) (392.2 ) 123.5 Effect of exchange rate differences on cash, cash equivalents and restricted cash — — — 0.6 — 0.6 Net increase (decrease) in cash, cash equivalents and restricted cash — 37.2 — (15.6 ) 0.9 22.5 Cash, cash equivalents and restricted cash at beginning of period — 5.5 — 53.3 (3.2 ) 55.6 Cash, cash equivalents and restricted cash at end of period $ — $ 42.7 $ — $ 37.7 $ (2.3 ) $ 78.1 Cash and cash equivalents $ — $ 42.7 $ — $ 34.2 $ (2.3 ) $ 74.6 Restricted cash (included in Other current assets) — — — 3.5 — 3.5 Cash, cash equivalents and restricted cash $ — $ 42.7 $ — $ 37.7 $ (2.3 ) $ 78.1 For the three months ended March 31, 2016 Aleris Corporation (Parent) Aleris International, Inc. Guarantor Subsidiaries Non-Guarantor Subsidiaries Eliminations Consolidated Net cash provided (used) by operating activities $ 0.4 $ (115.0 ) $ 100.3 $ 26.0 $ (0.5 ) $ 11.2 Investing activities Payments for property, plant and equipment — — (99.7 ) (22.3 ) — (122.0 ) Return of investments in subsidiaries — 5.0 0.1 — (5.1 ) — Other — — — (0.1 ) — (0.1 ) Net cash provided (used) by investing activities — 5.0 (99.6 ) (22.4 ) (5.1 ) (122.1 ) Financing activities Proceeds from revolving credit facilities — 110.0 — — — 110.0 Payments on revolving credit facilities — — — (0.2 ) — (0.2 ) Net proceeds from (payments on) other long-term debt — 0.1 (0.3 ) (0.1 ) — (0.3 ) Debt issuance costs — (0.4 ) — — — (0.4 ) Dividends paid — — (0.3 ) (5.3 ) 5.6 — Other (0.4 ) 0.3 (0.1 ) (0.2 ) — (0.4 ) Net cash (used) provided by financing activities (0.4 ) 110.0 (0.7 ) (5.8 ) 5.6 108.7 Effect of exchange rate differences on cash, cash equivalents and restricted cash — — — 1.9 — 1.9 Net decrease in cash, cash equivalents and restricted cash — — — (0.3 ) — (0.3 ) Cash, cash equivalents and restricted cash at beginning of period — — — 62.2 — 62.2 Cash, cash equivalents and restricted cash at end of period $ — $ — $ — $ 61.9 $ — $ 61.9

Basis Of Presentation and Rec28

Basis Of Presentation and Recent Accounting Pronouncements (Details) - Accounting Standards Update 2016-16 [Member] $ in Millions	Dec. 31, 2016USD ($)
Prepaid Expenses and Other Current Assets [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (8.2)
Deferred Tax Asset [Domain]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	3.6
Other Comprehensive Income [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	0.1
Retained Earnings [Member]
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption	$ (4.7)

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 186.4	$ 181.7
Work in process	233.9	195.4
Finished goods	161.6	134
Supplies	28.3	27.8
Total inventories	$ 610.2	$ 538.9

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($)	Feb. 14, 2017	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Apr. 04, 2016
Debt Instrument [Line Items]
Total debt		$ 1,593,300,000		$ 1,466,200,000
Less: Current portion of long-term debt		28,500,000		27,700,000
Total long-term debt		1,564,800,000		1,438,500,000
Proceeds from senior secured notes, inclusive of premiums		263,800,000	$ 0
Line of Credit \| ABL Facility
Debt Instrument [Line Items]
Total debt		120,700,000		255,300,000
Senior Notes \| 7 7/8% Senior Notes
Debt Instrument [Line Items]
Total debt		435,800,000		435,500,000
Debt discount		$ 4,200,000		4,500,000
Stated interest rate		7.875%
Senior Notes \| 9 1/2% Senior Notes
Debt Instrument [Line Items]
Total debt		$ 801,000,000		538,400,000
Debt discount		$ 1,000,000		11,600,000
Stated interest rate		9.50%
Senior Notes \| 9 1/2% Senior Notes, Issued February 2017
Debt Instrument [Line Items]
Stated interest rate	9.50%
Debt instrument, face amount	$ 250,000,000
Proceeds from senior secured notes, inclusive of premiums	$ 263,800,000
Senior Notes \| 9 1/2% Senior Notes, Issued April 2016
Debt Instrument [Line Items]
Stated interest rate					9.50%
Debt instrument, face amount					$ 550
Senior Subordinated Notes \| Senior Subordinated Exchangeable Notes
Debt Instrument [Line Items]
Total debt		$ 44,400,000		44,400,000
Debt discount		400,000		400,000
Notes Payable to Banks \| Zhenjiang term loans
Debt Instrument [Line Items]
Total debt		163,800,000		164,500,000
Debt discount		100,000		100,000
Foreign Line of Credit \| Zhenjiang revolver
Debt Instrument [Line Items]
Total debt		21,900,000		22,000,000
Debt discount		100,000		100,000
Other Long-term Debt
Debt Instrument [Line Items]
Total debt		$ 5,700,000		$ 6,100,000

Commitments And Contingencies (

Commitments And Contingencies (Details) $ in Millions	3 Months Ended
Commitments And Contingencies (Details) $ in Millions	Mar. 31, 2017USD ($)Foreign_CountriesStatesSite	Dec. 31, 2016USD ($)
Loss Contingencies [Line Items]
Number of Superfund sites with operations and maintenance \| Site	2
Number of states in which company performs environmental remediation \| States	4
Number of foreign countries with environmental remediations \| Foreign_Countries	1
Number of sites with environmental remediations \| Site	7
Portion of environmental liabilities indemnified by Corus Group Ltd.	$ 11.4	$ 11.5
Asset retirement obligations	$ 4.7	4.7
Estimated time frame of disbursements	10 years
Other Long-Term Liabilities and Accrued Liabilities
Loss Contingencies [Line Items]
Reserves for environmental remediation liabilities	$ 23.7	$ 23.8

Stockholders' Equity (Schedule

Stockholders' Equity (Schedule of Stockholders' Equity) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Increase (Decrease) in Stockholders' Equity Disclosure [Roll Forward]
Total Equity at beginning of period	$ 216.6
Total Equity at end of period	185.9
Aleris Corporation
Increase (Decrease) in Stockholders' Equity Disclosure [Roll Forward]
Total Equity at beginning of period	216.6
Net income attributable to Aleris Corporation	(35.2)
Other comprehensive income	9.6
Stock-based compensation activity	(0.4)
Adoption of new accounting standards	(4.7)
Total Equity at end of period	$ 185.9

Stockholders' Equity (Changes i

Stockholders' Equity (Changes in the Number of Outstanding Common Stock) (Details)	3 Months Ended
	Mar. 31, 2017shares
Outstanding Shares of Common Stock [Roll Forward]
Balance at January 1, 2017	31,904,250
Balance at March 31, 2017	31,989,712
Restricted Stock
Outstanding Shares of Common Stock [Roll Forward]
Issuance associated with vested restricted stock units	85,462

Accumulated Other Comprehensi34

Accumulated Other Comprehensive Loss (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)
Accumulated Other Comprehensive Income [Roll Forward]
Balance at January 1, 2017	$ (223.5)
Current period currency translation adjustments	8.7
Amortization of net actuarial losses and prior service costs, net of tax	0.9
Balance at March 31, 2017	(213.9)
Currency translation
Accumulated Other Comprehensive Income [Roll Forward]
Balance at January 1, 2017	(150.9)
Current period currency translation adjustments	9.4
Amortization of net actuarial losses and prior service costs, net of tax	0
Balance at March 31, 2017	(141.5)
Pension and other postretirement
Accumulated Other Comprehensive Income [Roll Forward]
Balance at January 1, 2017	(72.6)
Current period currency translation adjustments	(0.7)
Amortization of net actuarial losses and prior service costs, net of tax	0.9
Balance at March 31, 2017	(72.4)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income [Roll Forward]
Amortization of net actuarial losses and prior service costs	(1.1)
Deferred tax benefit on pension and other postretirement liability adjustments	0.2
Losses reclassified into earnings, net of tax	$ (0.9)

Segment Information (Schedule o

Segment Information (Schedule of Revenues and Segment Income) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017USD ($)Operating_Segment	Mar. 31, 2016USD ($)
Segment Reporting Information [Line Items]
Number of operating segments \| Operating_Segment	3
Revenue for Reportable Segments
Revenues	$ 674.2	$ 662.5
Segment income	63.6	58
External Customers
Revenue for Reportable Segments
Revenues	674.2	662.5
Intra-entity
Revenue for Reportable Segments
Revenues	0	0
Operating segments \| North America
Revenue for Reportable Segments
Revenues	351.6	334.1
Segment income	24.2	24.2
Operating segments \| Europe
Revenue for Reportable Segments
Revenues	309	312.7
Segment income	38	32.9
Operating segments \| Asia Pacific
Revenue for Reportable Segments
Revenues	24.2	21.3
Segment income	1.4	0.9
Operating segments \| External Customers \| North America
Revenue for Reportable Segments
Revenues	348.5	333.9
Operating segments \| External Customers \| Europe
Revenue for Reportable Segments
Revenues	302.6	309.1
Operating segments \| External Customers \| Asia Pacific
Revenue for Reportable Segments
Revenues	23.1	19.5
Operating segments \| Intra-entity \| North America
Revenue for Reportable Segments
Revenues	3.1	0.2
Operating segments \| Intra-entity \| Europe
Revenue for Reportable Segments
Revenues	6.4	3.6
Operating segments \| Intra-entity \| Asia Pacific
Revenue for Reportable Segments
Revenues	1.1	1.8
Intra-entity Eliminations \| Intra-entity
Revenue for Reportable Segments
Revenues	$ (10.6)	$ (5.6)

Segment Information (Reconcilia

Segment Information (Reconciliation of Segment Income to Consolidated Statements of Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Depreciation and amortization	$ (25.7)	$ (26.3)
Restructuring charges	(0.4)	(0.8)
Interest expense, net	(27.1)	(18.1)
Unallocated (losses) gains on derivative financial instruments	(28.2)	1
(Loss) income before income taxes	(24.5)	2.4
Operating segments
Segment Reporting Information [Line Items]
Net income attributable to Aleris Corporation	63.6	58
Unallocated Amounts
Segment Reporting Information [Line Items]
Depreciation and amortization	(25.7)	(26.3)
Other corporate general and administrative expenses	(12.4)	(13.1)
Restructuring charges	(0.4)	(0.8)
Interest expense, net	(27.1)	(18.1)
Unallocated (losses) gains on derivative financial instruments	(7.7)	9.2
Unallocated currency exchange losses	(0.1)	(0.1)
Start-up costs	(14.5)	(6.3)
Other expense, net	$ (0.2)	$ (0.1)

Segment Information (Reconcil37

Segment Information (Reconciliation of Reportable Segment Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 2,563.7	$ 2,389.9
Operating segments \| North America
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,280	1,180.2
Operating segments \| Europe
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	697.2	645.3
Operating segments \| Asia Pacific
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	354.8	358.6
Unallocated Amounts
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 231.7	$ 205.8

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Millions	Jun. 01, 2010	Mar. 31, 2017	Mar. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Life of award (in years)	10 years
Award vesting period (in years)	4 years
Stock options granted (in shares)		0
Stock options forfeited (in shares)		21,291
Stock-based compensation expense		$ 0.6	$ 1.7

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Effective tax rate (percent)	(43.20%)	365.40%
Unrecognized tax benefits	$ 2.4
Accrued interest related to uncertain tax positions	$ 0.7

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Millions	3 Months Ended
Employee Benefit Plans (Details) - USD ($) $ in Millions	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Amortization of net actuarial losses (gains)	$ (0.9)
U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	$ 0.9
Interest cost	1.4	1.5
Amortization of net actuarial losses (gains)	0.5	0.5
Amortization of prior service cost	0.1	0.1
Expected return on plan assets	(2.6)	(2.5)
Net periodic benefit expense	0.4	0.5
European Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	0.9	0.5
Interest cost	0.4	0.5
Amortization of net actuarial losses (gains)	0.7	0.4
Net periodic benefit expense	2	1.4
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Interest cost	0.3	0.3
Amortization of net actuarial losses (gains)	(0.1)	0
Net periodic benefit expense	$ 0.2	$ 0.3

Derivative And Other Financia41

Derivative And Other Financial Instruments (Narratives) (Details) gal in Millions, T in Millions, BTU in Trillions	3 Months Ended	12 Months Ended
	Mar. 31, 2017EUR (€)BTUgalT	Dec. 31, 2016EUR (€)BTUgalT	Mar. 31, 2017USD ($)BTUgalT	Dec. 31, 2016USD ($)BTUgalT
Derivative [Line Items]
Cash collateral posted \| $			$ 0	$ 0
Metal
Derivative [Line Items]
Maximum settlement period of derivatives (in months)	3 months
Tons of metal in forward contracts with the right to buy (in tons)	0.1	0.2	0.1	0.2
Tons of metal in forward contracts with the right to sell (in tons)	0.2	0.2	0.2	0.2
Energy Related Derivative
Derivative [Line Items]
British thermal units in forward buy contracts (in British thermal units) \| BTU	1.8	2.1	1.8	2.1
Gallons in diesel swap contracts (in gallons) \| gal	0	0	0	0
Currency
Derivative [Line Items]
Euros in forward contracts \| €	€ 38,500,000	€ 34,600,000
Convertible Notes Payable
Derivative [Line Items]
Risk-free interest rate (percent)	1.50%	1.60%
Expected equity volatility rate (percent)	40.00%	45.00%
Zhenjiang term loans
Derivative [Line Items]
Maximum period for variable interest rate paid (in months)	6 months
Senior Notes \| 7 7/8% Senior Notes
Derivative [Line Items]
Stated interest rate	7.875%		7.875%
Senior Notes \| 9 1/2% Senior Notes
Derivative [Line Items]
Stated interest rate	9.50%		9.50%

Derivative And Other Financia42

Derivative And Other Financial Instruments (Schedule of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Asset
Fair value	$ 20.2	$ 9.6
Effect of counterparty netting	(16.9)	(6.6)
Net derivatives as classified in the balance sheet	3.3	3
Liability
Fair value	(33)	(14.6)
Effect of counterparty netting	16.9	6.6
Net derivatives as classified in the balance sheet	(16.1)	(8)
Metal
Asset
Fair value	20	8.9
Liability
Fair value	(31.3)	(12.3)
Energy Related Derivative
Asset
Fair value	0.1	0.7
Liability
Fair value	(0.1)	0
Currency
Asset
Fair value	0.1	0
Liability
Fair value	$ (1.6)	$ (2.3)

Derivative And Other Financia43

Derivative And Other Financial Instruments (Schedule of Derivative Instruments in Balance Sheet by Contract Type) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Prepaid expenses and other current assets	$ 36.6	$ 33.4
Other long-term assets	67.6	72.2
Total Asset Derivatives	3.3	3
Accrued liabilities	224.6	201.4
Other long-term liabilities	63.2	63.7
Total Liability Derivatives	16.1	8
Metal
Derivatives, Fair Value [Line Items]
Prepaid expenses and other current assets	0.3	2.3
Other long-term assets	3	0
Accrued liabilities	14.6	5.1
Other long-term liabilities	0	0.6
Energy Related Derivative
Derivatives, Fair Value [Line Items]
Prepaid expenses and other current assets	0	0.7
Currency
Derivatives, Fair Value [Line Items]
Accrued liabilities	1.5	1.8
Other long-term liabilities	$ 0	$ 0.5

Derivative And Other Financia44

Derivative And Other Financial Instruments (Schedule of Realized (Gains) Losses on Derivatives) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Metal
Derivative Instruments, Loss [Line Items]
Realized (gains) losses on derivative financial instruments	$ 19.5	$ 7.3
Energy Related Derivative
Derivative Instruments, Loss [Line Items]
Realized (gains) losses on derivative financial instruments	0.4	0.6
Currency
Derivative Instruments, Loss [Line Items]
Realized (gains) losses on derivative financial instruments	$ 0.5	$ 0.3

Derivative And Other Financia45

Derivative And Other Financial Instruments (Schedule of Fair Value for Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 74.6	$ 55.6
Restricted cash	3.5	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivables held in escrow	20.6	20.6
Lines of credit	120.7	255.3
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchangeable Notes	81.4	81.4
7 7/8% Senior Notes \| Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	431.1	441.7
9 1/2% Senior Notes \| Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	862	594
Zhenjiang term loans \| Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Zhenjiang Term Loans	164.3	165
Zhenjiang revolver \| Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Lines of credit	22	22.1
Carrying Amount \| Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	74.6	55.6
Restricted cash	3.5	0
Carrying Amount \| Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivables held in escrow	17	17
Lines of credit	120.7	255.3
Carrying Amount \| Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchangeable Notes	44.4	44.4
Carrying Amount \| 7 7/8% Senior Notes \| Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	435.8	435.5
Carrying Amount \| 9 1/2% Senior Notes \| Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes	801	538.4
Carrying Amount \| Zhenjiang term loans \| Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Zhenjiang Term Loans	163.8	164.5
Carrying Amount \| Zhenjiang revolver \| Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Lines of credit	$ 21.9	$ 22

Potential Acquisition Of Aler46

Potential Acquisition Of Aleris Corporation (Details) $ in Millions	Aug. 29, 2016USD ($)
Zhongwang USA LLC
Business Acquisition [Line Items]
Agreed upon payment	$ 1,110

Condensed Consolidating Finan47

Condensed Consolidating Financial Statements (Condensed Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Current Assets
Cash and cash equivalents	$ 74.6	$ 55.6	$ 61.9
Accounts receivable, net	271.3	218.7
Inventories	610.2	538.9
Prepaid expenses and other current assets	36.6	33.4
Intercompany receivables	0	0
Total Current Assets	992.7	846.6
Property, plant and equipment, net	1,375.2	1,346
Intangible assets, net	36.3	36.8
Deferred income taxes	91.9	88.3
Other long-term assets	67.6	72.2
Investments in subsidiaries	0	0
Total Assets	2,563.7	2,389.9
Current Liabilities
Accounts payable	294.1	246.6
Accrued liabilities	224.6	201.4
Current portion of long-term debt	28.5	27.7
Intercompany payables	0	0
Total Current Liabilities	547.2	475.7
Long-term debt	1,564.8	1,438.5
Deferred Tax Liabilities, Net, Noncurrent	9.2	2.8
Accrued pension benefits	159.8	158.4
Accrued postretirement benefits	33.6	34.2
Other long-term liabilities	63.2	63.7
Total Long-Term Liabilities	1,830.6	1,697.6
Total equity	185.9	216.6
Total Liabilities and Equity	2,563.7	2,389.9
Eliminations
Current Assets
Cash and cash equivalents	(2.3)	(3.2)
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	0	0
Intercompany receivables	(432.3)	(1,358.6)
Total Current Assets	(434.6)	(1,361.8)
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Deferred income taxes	0	0
Other long-term assets	0	0
Investments in subsidiaries	(1,642.1)	(1,310)
Total Assets	(2,076.7)	(2,671.8)
Current Liabilities
Accounts payable	(2.3)	(3.2)
Accrued liabilities	0	0
Current portion of long-term debt	0	0
Intercompany payables	(432.3)	(1,358.6)
Total Current Liabilities	(434.6)	(1,361.8)
Long-term debt	0	0
Deferred Tax Liabilities, Net, Noncurrent	0	0
Accrued pension benefits	0	0
Accrued postretirement benefits	0	0
Other long-term liabilities	0	0
Total Long-Term Liabilities	0	0
Total equity	(1,642.1)	(1,310)
Total Liabilities and Equity	(2,076.7)	(2,671.8)
Aleris Corporation (Parent) \| Reportable Legal Entities
Current Assets
Cash and cash equivalents	0	0
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	0	0
Intercompany receivables	0	0
Total Current Assets	0	0
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Deferred income taxes	0	0
Other long-term assets	0	0
Investments in subsidiaries	187.8	217.6
Total Assets	187.8	217.6
Current Liabilities
Accounts payable	0	0
Accrued liabilities	0	0
Current portion of long-term debt	0	0
Intercompany payables	1.9	1
Total Current Liabilities	1.9	1
Long-term debt	0	0
Deferred Tax Liabilities, Net, Noncurrent	0	0
Accrued pension benefits	0	0
Accrued postretirement benefits	0	0
Other long-term liabilities	0	0
Total Long-Term Liabilities	0	0
Total equity	185.9	216.6
Total Liabilities and Equity	187.8	217.6
Aleris International, Inc. \| Reportable Legal Entities
Current Assets
Cash and cash equivalents	42.7	5.5
Accounts receivable, net	0	0
Inventories	0	0
Prepaid expenses and other current assets	0.6	0
Intercompany receivables	208	897.9
Total Current Assets	251.3	903.4
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Deferred income taxes	0	0
Other long-term assets	11.7	10.8
Investments in subsidiaries	1,457.4	1,089.6
Total Assets	1,720.4	2,003.8
Current Liabilities
Accounts payable	2.2	1.8
Accrued liabilities	53.3	19.8
Current portion of long-term debt	0	0
Intercompany payables	195.9	616.2
Total Current Liabilities	251.4	637.8
Long-term debt	1,281.2	1,148.4
Deferred Tax Liabilities, Net, Noncurrent	0	0
Accrued pension benefits	0	0
Accrued postretirement benefits	0	0
Other long-term liabilities	0	0
Total Long-Term Liabilities	1,281.2	1,148.4
Total equity	187.8	217.6
Total Liabilities and Equity	1,720.4	2,003.8
Guarantor Subsidiaries \| Reportable Legal Entities
Current Assets
Cash and cash equivalents	0	0
Accounts receivable, net	107.9	81
Inventories	286.1	240.8
Prepaid expenses and other current assets	14.6	15.2
Intercompany receivables	64.7	296.5
Total Current Assets	473.3	633.5
Property, plant and equipment, net	848.9	819.1
Intangible assets, net	20.4	20.9
Deferred income taxes	0	0
Other long-term assets	6.1	6.1
Investments in subsidiaries	(3.1)	2.8
Total Assets	1,345.6	1,482.4
Current Liabilities
Accounts payable	155.6	126.1
Accrued liabilities	90.5	109.3
Current portion of long-term debt	0.4	0.5
Intercompany payables	218.2	719.6
Total Current Liabilities	464.7	955.5
Long-term debt	0.5	0.6
Deferred Tax Liabilities, Net, Noncurrent	0.2	0.2
Accrued pension benefits	43.7	44.1
Accrued postretirement benefits	33.6	34.2
Other long-term liabilities	36.7	36.5
Total Long-Term Liabilities	114.7	115.6
Total equity	766.2	411.3
Total Liabilities and Equity	1,345.6	1,482.4
Non-Guarantor Subsidiaries \| Reportable Legal Entities
Current Assets
Cash and cash equivalents	34.2	53.3
Accounts receivable, net	163.4	137.7
Inventories	324.1	298.1
Prepaid expenses and other current assets	21.4	18.2
Intercompany receivables	159.6	164.2
Total Current Assets	702.7	671.5
Property, plant and equipment, net	526.3	526.9
Intangible assets, net	15.9	15.9
Deferred income taxes	91.9	88.3
Other long-term assets	49.8	55.3
Investments in subsidiaries	0	0
Total Assets	1,386.6	1,357.9
Current Liabilities
Accounts payable	138.6	121.9
Accrued liabilities	80.8	72.3
Current portion of long-term debt	28.1	27.2
Intercompany payables	16.3	21.8
Total Current Liabilities	263.8	243.2
Long-term debt	283.1	289.5
Deferred Tax Liabilities, Net, Noncurrent	9	2.6
Accrued pension benefits	116.1	114.3
Accrued postretirement benefits	0	0
Other long-term liabilities	26.5	27.2
Total Long-Term Liabilities	434.7	433.6
Total equity	688.1	681.1
Total Liabilities and Equity	$ 1,386.6	$ 1,357.9
7 7/8% Senior Notes \| Senior Notes
Condensed Financial Statements, Captions [Line Items]
Stated interest rate	7.875%
9 1/2% Senior Notes \| Senior Notes
Condensed Financial Statements, Captions [Line Items]
Stated interest rate	9.50%

Condensed Consolidating Finan48

Condensed Consolidating Financial Statements (Condensed Income Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 674.2	$ 662.5
Cost of sales	589.1	589
Gross profit	85.1	73.5
Selling, general and administrative expenses	53.2	50.3
Restructuring charges	0.4	0.8
(Gains) losses on derivative financial instruments	28.2	(1)
Other operating expense, net	1	0.4
Operating income	2.3	23
Interest expense, net	27.1	18.1
Other (income) expense, net	(0.3)	2.5
Equity in net loss (earnings) of affiliates	0	0
(Loss) income before income taxes	(24.5)	2.4
Provision for (benefit from) income taxes	10.7	8.7
Net loss	(35.2)	(6.3)
Comprehensive (loss) income	(25.6)	16.6
Eliminations
Condensed Financial Statements, Captions [Line Items]
Revenues	(7.3)	(3.7)
Cost of sales	(7.3)	(3.7)
Gross profit	0	0
Selling, general and administrative expenses	0	0
Restructuring charges	0	0
(Gains) losses on derivative financial instruments	0	0
Other operating expense, net	0	0
Operating income	0	0
Interest expense, net	0	0
Other (income) expense, net	0	0
Equity in net loss (earnings) of affiliates	(70.3)	(14.6)
(Loss) income before income taxes	70.3	14.6
Provision for (benefit from) income taxes	0	0
Net loss	70.3	14.6
Comprehensive (loss) income	51	(31.3)
Aleris Corporation (Parent) \| Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0
Cost of sales	0	0
Gross profit	0	0
Selling, general and administrative expenses	0	0
Restructuring charges	0	0
(Gains) losses on derivative financial instruments	0	0
Other operating expense, net	0	0
Operating income	0	0
Interest expense, net	0	0
Other (income) expense, net	0	0
Equity in net loss (earnings) of affiliates	35.2	6.3
(Loss) income before income taxes	(35.2)	(6.3)
Provision for (benefit from) income taxes	0	0
Net loss	(35.2)	(6.3)
Comprehensive (loss) income	(25.6)	16.6
Aleris International, Inc. \| Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Revenues	0	0
Cost of sales	0	0
Gross profit	0	0
Selling, general and administrative expenses	0.1	1.3
Restructuring charges	0	0
(Gains) losses on derivative financial instruments	0	0
Other operating expense, net	0	0
Operating income	(0.1)	(1.3)
Interest expense, net	0	0
Other (income) expense, net	(0.3)	(3.7)
Equity in net loss (earnings) of affiliates	35.3	8.7
(Loss) income before income taxes	(35.1)	(6.3)
Provision for (benefit from) income taxes	0.1	0
Net loss	(35.2)	(6.3)
Comprehensive (loss) income	(25.6)	16.6
Guarantor Subsidiaries \| Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Revenues	349.4	334.1
Cost of sales	324.6	306.7
Gross profit	24.8	27.4
Selling, general and administrative expenses	32.4	28.6
Restructuring charges	0.3	0.3
(Gains) losses on derivative financial instruments	20	1.7
Other operating expense, net	1	0.3
Operating income	(28.9)	(3.5)
Interest expense, net	20.7	9.8
Other (income) expense, net	(1.2)	(1.2)
Equity in net loss (earnings) of affiliates	(0.2)	(0.4)
(Loss) income before income taxes	(48.2)	(11.7)
Provision for (benefit from) income taxes	(0.1)	(0.2)
Net loss	(48.1)	(11.5)
Comprehensive (loss) income	(47.6)	(10.5)
Non-Guarantor Subsidiaries \| Reportable Legal Entities
Condensed Financial Statements, Captions [Line Items]
Revenues	332.1	332.1
Cost of sales	271.8	286
Gross profit	60.3	46.1
Selling, general and administrative expenses	20.7	20.4
Restructuring charges	0.1	0.5
(Gains) losses on derivative financial instruments	8.2	(2.7)
Other operating expense, net	0	0.1
Operating income	31.3	27.8
Interest expense, net	6.4	8.3
Other (income) expense, net	1.2	7.4
Equity in net loss (earnings) of affiliates	0	0
(Loss) income before income taxes	23.7	12.1
Provision for (benefit from) income taxes	10.7	8.9
Net loss	13	3.2
Comprehensive (loss) income	$ 22.2	$ 25.2

Condensed Consolidating Finan49

Condensed Consolidating Financial Statements (Condensed Cash Flow Statement) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	$ (38.6)	$ 11.2
Investing activities
Payments for property, plant and equipment	(62.6)	(122)
Equity contributions in subsidiaries	0
Return of investment in subsidiaries	0	0
Other	(0.4)	(0.1)
Net cash used by investing activities	(63)	(122.1)
Financing activities
Proceeds from revolving credit facilities	159.5	110
Payments on revolving credit facilities	(294.5)	(0.2)
Proceeds from senior secured notes, inclusive of premiums	263.8	0
Payments on other long-term debt	(2.3)	(0.3)
Debt issuance costs	(1.8)	(0.4)
Proceeds from intercompany equity contributions	0
Dividends paid	0	0
Other	(1.2)	(0.4)
Net cash provided by financing activities	123.5	108.7
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0.6	1.9
Net increase (decrease) in cash, cash equivalents and restricted cash	22.5	(0.3)
Cash, cash equivalents and restricted cash at beginning of period	55.6	62.2
Cash, cash equivalents and restricted cash at end of period	78.1	61.9
Cash and cash equivalents			$ 74.6	$ 55.6	$ 61.9
Restricted cash (included in Other current assets)			3.5		0
Cash, cash equivalents and restricted cash	55.6	62.2	78.1	55.6	61.9
Reportable Legal Entities \| Aleris Corporation (Parent)
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	1.1	0.4
Investing activities
Payments for property, plant and equipment	0	0
Equity contributions in subsidiaries	0
Return of investment in subsidiaries	0	0
Other	0	0
Net cash used by investing activities	0	0
Financing activities
Proceeds from revolving credit facilities	0	0
Payments on revolving credit facilities	0	0
Proceeds from senior secured notes, inclusive of premiums	0
Payments on other long-term debt	0	0
Debt issuance costs		0
Proceeds from intercompany equity contributions	0
Dividends paid	0	0
Other	(1.1)	(0.4)
Net cash provided by financing activities	(1.1)	(0.4)
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0
Cash and cash equivalents			0	0
Restricted cash (included in Other current assets)			0
Cash, cash equivalents and restricted cash	0	0	0	0	0
Reportable Legal Entities \| Aleris International, Inc.
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	303.5	(115)
Investing activities
Payments for property, plant and equipment	0	0
Equity contributions in subsidiaries	(406.6)
Return of investment in subsidiaries	8.3	5
Other	0	0
Net cash used by investing activities	(398.3)	5
Financing activities
Proceeds from revolving credit facilities	55	110
Payments on revolving credit facilities	(185)	0
Proceeds from senior secured notes, inclusive of premiums	263.8
Payments on other long-term debt	0	0.1
Debt issuance costs	(1.8)	(0.4)
Proceeds from intercompany equity contributions	0
Dividends paid	0	0
Other	0	0.3
Net cash provided by financing activities	132	110
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	37.2	0
Cash, cash equivalents and restricted cash at beginning of period	5.5	0
Cash, cash equivalents and restricted cash at end of period	42.7	0
Cash and cash equivalents			42.7	5.5
Restricted cash (included in Other current assets)			0
Cash, cash equivalents and restricted cash	5.5	0	42.7	5.5	0
Reportable Legal Entities \| Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	(355.6)	100.3
Investing activities
Payments for property, plant and equipment	(52.7)	(99.7)
Equity contributions in subsidiaries	0
Return of investment in subsidiaries	5.8	0.1
Other	(0.4)	0
Net cash used by investing activities	(47.3)	(99.6)
Financing activities
Proceeds from revolving credit facilities	0	0
Payments on revolving credit facilities	0	0
Proceeds from senior secured notes, inclusive of premiums	0
Payments on other long-term debt	(0.1)	(0.3)
Debt issuance costs	0	0
Proceeds from intercompany equity contributions	402.6
Dividends paid	0	(0.3)
Other	0.4	(0.1)
Net cash provided by financing activities	402.9	(0.7)
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0	0
Cash, cash equivalents and restricted cash at beginning of period	0	0
Cash, cash equivalents and restricted cash at end of period	0	0
Cash and cash equivalents			0	0
Restricted cash (included in Other current assets)			0
Cash, cash equivalents and restricted cash	0	0	0	0	0
Reportable Legal Entities \| Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	11.8	26
Investing activities
Payments for property, plant and equipment	(9.9)	(22.3)
Equity contributions in subsidiaries	0
Return of investment in subsidiaries	0	0
Other	0	(0.1)
Net cash used by investing activities	(9.9)	(22.4)
Financing activities
Proceeds from revolving credit facilities	104.5	0
Payments on revolving credit facilities	(109.5)	(0.2)
Proceeds from senior secured notes, inclusive of premiums	0
Payments on other long-term debt	(2.2)	(0.1)
Debt issuance costs	0	0
Proceeds from intercompany equity contributions	4
Dividends paid	(14.4)	(5.3)
Other	(0.5)	(0.2)
Net cash provided by financing activities	(18.1)	(5.8)
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0.6	1.9
Net increase (decrease) in cash, cash equivalents and restricted cash	(15.6)	(0.3)
Cash, cash equivalents and restricted cash at beginning of period	53.3	62.2
Cash, cash equivalents and restricted cash at end of period	37.7	61.9
Cash and cash equivalents			34.2	53.3
Restricted cash (included in Other current assets)			3.5
Cash, cash equivalents and restricted cash	53.3	62.2	37.7	53.3	61.9
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided (used) by operating activities	0.6	(0.5)
Investing activities
Payments for property, plant and equipment	0	0
Equity contributions in subsidiaries	406.6
Return of investment in subsidiaries	(14.1)	(5.1)
Other	0	0
Net cash used by investing activities	392.5	(5.1)
Financing activities
Proceeds from revolving credit facilities	0	0
Payments on revolving credit facilities	0	0
Proceeds from senior secured notes, inclusive of premiums	0
Payments on other long-term debt	0	0
Debt issuance costs	0	0
Proceeds from intercompany equity contributions	(406.6)
Dividends paid	14.4	5.6
Other	0	0
Net cash provided by financing activities	(392.2)	5.6
Effect of exchange rate differences on cash, cash equivalents and restricted cash	0	0
Net increase (decrease) in cash, cash equivalents and restricted cash	0.9	0
Cash, cash equivalents and restricted cash at beginning of period	(3.2)	0
Cash, cash equivalents and restricted cash at end of period	(2.3)	0
Cash and cash equivalents			(2.3)	(3.2)
Restricted cash (included in Other current assets)			0
Cash, cash equivalents and restricted cash	$ (3.2)	$ 0	$ (2.3)	$ (3.2)	$ 0