Century Aluminum (CENX) 10-Q 4 Nov 15 2015 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	CENTURY ALUMINUM CO
Entity Central Index Key	949,157
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Amendment Flag	false
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		86,931,703

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
NET SALES:
Related parties	$ 428,018	$ 324,775	$ 1,517,428	$ 898,931
Third-party customers	26,522	175,857	48,514	480,872
Total net sales	454,540	500,632	1,565,942	1,379,803
Cost of goods sold	496,963	424,918	1,505,928	1,267,343
Gross profit (loss)	(42,423)	75,714	60,014	112,460
Selling, general and administrative expenses	11,566	12,146	33,549	32,826
Ravenswood impairment	0	0	30,850	0
Other operating expense – net	1,537	1,417	6,217	5,705
Operating income (loss)	(55,526)	62,151	(10,602)	73,929
Interest expense	(5,418)	(5,493)	(16,542)	(16,541)
Interest income	45	23	248	197
Net gain (loss) on forward and derivative contracts	285	353	1,204	(174)
Unrealized gain on fair value of contingent consideration	1,523	0	18,337	0
Other income (expense) – net	114	(470)	1,261	(423)
Income (loss) before income taxes and equity in earnings of joint ventures	(58,977)	56,564	(6,094)	56,988
Income tax benefit (expense)	2,161	(6,444)	(12,205)	(7,004)
Income (loss) before equity in earnings of joint ventures	(56,816)	50,120	(18,299)	49,984
Equity in earnings of joint ventures	704	285	2,069	661
Net income (loss)	(56,112)	50,405	(16,230)	50,645
Net income (loss) allocated to common stockholders	$ (56,112)	$ 46,277	$ (16,230)	$ 46,487
EARNINGS (LOSS) PER COMMON SHARE:
Basic and Diluted (in dollars per share)	$ (0.65)	$ 0.52	$ (0.19)	$ 0.52
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (shares)	86,907	88,827	87,524	88,777
Diluted (shares)	86,907	89,532	87,524	89,372

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income (loss)	$ (56,112)	$ 50,405	$ (16,230)	$ 50,645
Other comprehensive income (loss) before income tax effect:
Net gain on foreign currency cash flow hedges reclassified as income	(46)	(46)	(139)	(139)
Defined benefit plans and other postretirement benefits:
Net gain (loss) arising during the period	(4,115)	0	12,145	440
Prior service benefit arising during the period	0	0	1,782	0
Amortization of prior service benefit during the period	(979)	(952)	(2,846)	(2,856)
Amortization of net loss during the period	1,899	1,402	6,022	4,207
Other comprehensive income (loss) income before income tax effect	(3,241)	404	16,964	1,652
Income tax effect	(383)	(557)	(1,148)	(1,837)
Other comprehensive income (loss)	(3,624)	(153)	15,816	(185)
Total comprehensive income (loss)	$ (59,736)	$ 50,252	$ (414)	$ 50,460

CONSOLIDATED BALANCE SHEETS (Un

CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 122,976	$ 163,242
Restricted cash	942	801
Accounts receivable — net	8,613	77,667
Due from affiliates	29,097	31,503
Inventories	298,859	283,480
Prepaid and other current assets	36,620	29,768
Assets held for sale	32,067	0
Deferred taxes	14,281	14,281
Total current assets	543,455	600,742
Property, plant and equipment — net	1,251,476	1,305,543
Other assets	111,770	118,773
TOTAL	1,906,701	2,025,058
LIABILITIES:
Accounts payable, trade	109,262	151,443
Due to affiliates	33,655	22,261
Accrued and other current liabilities	71,465	103,808
Accrued employee benefits costs	9,911	10,158
Industrial revenue bonds	7,815	7,815
Total current liabilities	232,108	295,485
Senior notes payable	247,178	246,888
Accrued pension benefits costs — less current portion	60,224	59,906
Accrued postretirement benefits costs — less current portion	135,665	152,894
Other liabilities	47,580	53,272
Deferred taxes	112,676	111,486
Total noncurrent liabilities	$ 603,323	$ 624,446
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY:
Series A Preferred stock (one cent par value, 5,000,000 shares authorized; 160,000 issued and 76,995 outstanding at September 30, 2015; 160,000 issued and 78,141 outstanding at December 31, 2014)	$ 1	$ 1
Common stock (one cent par value, 195,000,000 shares authorized; 94,118,224 issued and 86,931,703 outstanding at September 30, 2015; 93,851,103 issued and 89,064,582 outstanding at December 31, 2014)	941	939
Additional paid-in capital	2,513,168	2,510,261
Treasury stock, at cost	(86,276)	(49,924)
Accumulated other comprehensive loss	(101,866)	(117,682)
Accumulated deficit	(1,254,698)	(1,238,468)
Total shareholders’ equity	1,071,270	1,105,127
TOTAL	$ 1,906,701	$ 2,025,058

CONSOLIDATED BALANCE SHEETS (U5

CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Series A Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Series A Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Series A Preferred stock, shares issued (in shares)	160,000	160,000
Series A Preferred stock, shares outstanding (in shares)	76,995	78,141
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	195,000,000	195,000,000
Common stock, shares issued (in shares)	94,118,224	93,851,103
Common stock, shares outstanding (in shares)	86,931,703	89,064,582

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ (16,230)	$ 50,645
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Unrealized gain on fair value of contingent consideration	(18,337)	0
Unrealized gain on E.ON contingent obligation	(1,059)	(1,059)
Accrued and other plant curtailment costs — net	2,149	3,267
Lower of cost or market inventory adjustment	31,013	(1,247)
Depreciation	55,815	52,784
Ravenswood impairment	30,850	0
Sebree power contract amortization	0	(5,534)
Debt discount amortization	289	268
Pension and other postretirement benefits	(298)	1,432
Deferred income taxes	1,215	6,502
Stock-based compensation	1,381	957
Equity in earnings of joint ventures, net of dividends	(2,069)	(661)
Change in operating assets and liabilities:
Accounts receivable — net	69,055	5,608
Due from affiliates	2,406	(8,866)
Inventories	(46,392)	(889)
Prepaid and other current assets	3,435	3,035
Accounts payable, trade	(43,485)	(8,885)
Due to affiliates	11,395	11,336
Accrued and other current liabilities	(8,418)	(7,566)
Pension contribution - Mt. Holly	(34,595)	0
Other — net	(5,611)	(3,413)
Net cash provided by operating activities	32,509	97,714
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(38,075)	(26,865)
Nordural expansion — Helguvik	(230)	(277)
Purchase of carbon anode assets and improvements	(9,304)	(12,280)
Purchase of Sebree smelter	0	(1,042)
Purchase of remaining interest in Mt. Holly smelter	11,313	0
Proceeds from sale of property, plant and equipment	14	46
Restricted and other cash deposits	(141)	480
Net cash used in investing activities	(36,423)	(39,938)
CASH FLOWS FROM FINANCING ACTIVITIES:
Repayment of debt	0	(2,603)
Borrowings under revolving credit facilities	1,414	91,731
Repayments under revolving credit facilities	(1,414)	(97,731)
Repurchase of common stock	(36,352)	0
Issuance of common stock	0	149
Net cash used in financing activities	(36,352)	(8,454)
CHANGE IN CASH AND CASH EQUIVALENTS	(40,266)	49,322
Cash and cash equivalents, beginning of period	163,242	84,088
Cash and cash equivalents, end of period	$ 122,976	$ 133,410

General

General	9 Months Ended
	Sep. 30, 2015
General [Abstract]
General	General The accompanying unaudited interim consolidated financial statements of Century Aluminum Company should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2014 . In management’s opinion, the unaudited interim consolidated financial statements reflect all adjustments, which are of a normal and recurring nature, that are necessary for a fair presentation of financial results for the interim periods presented. Operating results for the first nine months of 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015 . Throughout this Form 10-Q, and unless expressly stated otherwise or as the context otherwise requires, "Century Aluminum," "Century," the "Company", "we," "us," "our" and "ours" refer to Century Aluminum Company and its consolidated subsidiaries.

Ravenswood impairment

Ravenswood impairment	9 Months Ended
	Sep. 30, 2015
Asset Impairment Charges [Abstract]
Ravenswood impairment	Ravenswood impairment At June 30, 2015, we recorded an impairment charge of $30,850 related to the Ravenswood, West Virginia aluminum smelter. The charge included $21,500 to write down property, plant and equipment to estimated net salvage value and $7,800 t o write down inventory to its net realizable value. We also accrued $1,550 for employee severance and other exit costs which are expected to be substantially paid by the end of 2015. On July 27, 2015, we announced the immediate and permanent closure of Ravenswood. The Ravenswood smelter has been idled since February 2009. The decision to permanently close the Ravenswood smelter was based on the inability to secure a competitive power contract for the smelter, compounded by challenging aluminum market conditions largely driven by increased exports of aluminum from China. As a result, the economics of restarting and operating the facility are unfavorable. The Ravenswood assets of $32,067 are classified as "Assets held for sale" on our Consolidated Balance Sheets as of September 30, 2015 and are expected to be sold over the next twelve months. The major components of the assets include inventory of $9,968 and property, plant and equipment of $22,099 .

Related party transactions

Related party transactions	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Related party transactions	Related party transactions A summary of the significant related party transactions for the three and nine months ended September 30, 2015 and 2014 is as follows: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Net sales to Glencore $ 428,018 $ 324,775 $ 1,517,428 $ 898,931 Purchases from Glencore 86,664 69,256 328,120 194,111 Purchases from BHH 13,515 10,715 41,768 38,438 We believe that all of the related party transactions were at prices that approximate market. Sales to Glencore Through its ownership of our common and preferred stock, Glencore has an overall 47.6% economic ownership in Century. We have entered into an agreement with Glencore pursuant to which we have agreed to sell, and Glencore has agreed to purchase, substantially all of our primary aluminum production in North America for 2015 and 2016 on a take-or-pay basis at market prices determined by reference to the Midwest Transaction Price plus additional negotiated product premiums. We sell primary aluminum produced at our Grundartangi facility under a long-term sales contract with Glencore at prices based on the London Metal Exchange ("LME") price for primary aluminum plus the European Duty Paid premium and any applicable product premiums less certain other costs. We also receive tolling fees from Glencore under tolling agreements that provide for delivery of primary aluminum produced at our Grundartangi facility. The fee paid by Glencore under these tolling agreements is based on the LME price for primary aluminum plus a portion of the European Duty Paid premium. We sold primary aluminum in 2014 to Glencore from our U.S. smelters on a spot basis at variable prices based on the LME, plus Midwest delivery and applicable product premiums. See Note 12 Forward contracts and financial instruments for additional information about our forward physical delivery contracts and tolling agreements with Glencore. Purchases from Glencore We purchase alumina from Glencore on both a spot basis and under a long-term supply agreement. Glencore has agreed to supply us with alumina through 2017 at prices indexed to the LME price of primary aluminum under a long-term supply agreement. In 2014, upon mutual agreement, approximately half of the purchases under this agreement were priced based on a published alumina index. For 2015, we have agreed to price all of the purchases under this agreement based on a published alumina index. We had additional agreements to buy alumina from Glencore which expired at the end of 2014. In 2014, the pricing on these alumina purchase agreements was indexed to the LME price for primary aluminum. Purchases from Baise Haohai Carbon Co., Ltd. ("BHH") We own a 40% stake in BHH, a joint venture that owns a carbon anode and cathode facility located in the Guangxi Zhuang Autonomous Region of south China. We have an agreement with BHH to provide carbon anodes to Grundartangi through December 31, 2015.

Business acquisitions

Business acquisitions	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Business acquisitions	Business acquisitions Acquisition of Mt. Holly aluminum smelter On October 23, 2014, our wholly-owned subsidiary, Berkeley Aluminum Inc. ("Berkeley") entered into a stock purchase agreement (the "Stock Purchase Agreement") with Alumax Inc. ("Alumax"), a wholly-owned subsidiary of Alcoa Inc. ("Alcoa"), to acquire Alcoa’s 50.3% stake in Mt. Holly. Upon closing of the transaction on December 1, 2014, Century owns 100% of Mt. Holly. Mt. Holly, located in Goose Creek, South Carolina, employed approximately 600 people and had an annual production capacity of 231,000 tonnes of primary aluminum as of the acquisition date. Pursuant to the terms of the Stock Purchase Agreement, Berkeley agreed to acquire all of the issued and outstanding shares of capital stock of Alumax of South Carolina Inc. ("Alumax of SC"), a wholly-owned subsidiary of Alumax, for $67,500 in cash subject to working capital and other similar adjustments. The acquisition was funded with available cash on hand. We incurred $1,087 of acquisition-related costs through December 31, 2014 and $417 during 2015. All acquisition-related costs were expensed to selling, general and administrative expenses in the period that they were incurred. The following table summarizes all of the elements of consideration for the transaction, including the preliminary estimated fair value of contingent consideration. Preliminary as of December 1, 2014 Purchase price $ 67,500 Contingent consideration 13,780 Economic, working capital and other closing adjustments (13,513 ) Total consideration transferred $ 67,767 Contingent Consideration - Earn-out provision The Stock Purchase Agreement provides for a post-closing cash payment to be made following December 31, 2015 based on (i) changes in the Midwest Transaction Price for aluminum between July 2, 2014 and December 31, 2015 and (ii) the aggregate cast house production of Mt. Holly from October 1, 2014 through December 31, 2015. The maximum amount of this post-closing cash payment by (i) Century Aluminum of South Carolina, Inc. ("CASC") to Alumax is $22,500 and (ii) Alumax to CASC is $12,500 . We recognized a $13,780 liability at December 1, 2014. Each period, until the end of the measurement period on December 31, 2015, we will remeasure the fair value of the contingent consideration with any changes in the fair value recognized in earnings. We classified the contingent consideration within Level 3 of the fair value hierarchy as its fair value was determined with inputs that are not readily observable in the market. For the three and nine months ended September 30, 2015 , we recognized $1,523 and $18,337 , respectively, in unrealized gain on fair value of contingent consideration, primarily related to decreases in the Midwest premium and the forward curve of the LME price of primary aluminum. Economic Adjustment, working capital and other adjustments The Stock Purchase Agreement provides for an economic adjustment that was established to put the parties in the same economic position as if the closing date for the acquisition had occurred on September 30, 2014. We received $11,189 from Alcoa for the economic adjustment in April 2015. The Stock Purchase Agreement also contained provisions for working capital adjustments. The working capital adjustment was based on actual working capital at closing compared to established working capital targets. We received $124 from Alcoa for the working capital adjustments in April 2015. Other adjustments include amounts due to Century for expected future post-employment benefit payments. We received $2,400 from Alcoa for these other adjustments at closing. Step Acquisition We accounted for this transaction as a step acquisition which required that we remeasure our prior 49.7% ownership interest, which was previously accounted for as an equity method investment, to fair value. The fair value of our interest in Mt. Holly was $47,700 , resulting in a non-cash pre-tax gain of $15,956 . $14,638 of that gain was recorded retroactively to the closing date resulting in an adjustment to Accumulated Deficit in the Consolidated Balance Sheets as of December 31, 2014. Our previously recorded equity method investment in Mt. Holly and the proportionally consolidated property, plant and equipment was derecognized from our Consolidated Balance Sheets. Since the date of the step acquisition, the financial results of Mt. Holly and all of its operating assets have been included within our consolidated financial statements. The allocation of the purchase price ( $67,767 ) and the fair value of the previous equity investment ( $47,700 ) to all of the assets acquired and liabilities assumed is based on the estimated fair values at the date of acquisition. The following purchase price allocation is preliminary and subject to change based on the finalization of the valuation of acquired assets and liabilities. Preliminary estimate of the acquisition date fair value as of December 1, 2014 Measurement period adjustments Adjusted preliminary estimate of the acquisition date fair value as of December 1, 2014 Assets Acquired: Inventories $ 26,105 $ (2,126 ) $ 23,979 Due from Alumax 20,786 (9,517 ) 11,269 Prepaid and other current assets 2,527 — 2,527 Intangible asset 2,580 — 2,580 Pension asset 30,842 — 30,842 Property, plant and equipment – net 127,089 15,748 142,837 Total assets acquired $ 209,929 $ 4,105 $ 214,034 Liabilities Assumed: Accounts payable, trade $ 41,471 $ — $ 41,471 Accrued and other current liabilities 8,335 255 8,590 Accrued pension benefit costs — 34,595 34,595 Accrued postretirement benefit costs 2,857 — 2,857 Asset retirement obligations 8,213 — 8,213 Deferred taxes 4,804 (2,118 ) 2,686 Total liabilities assumed $ 65,680 $ 32,732 $ 98,412 Goodwill $ 4,804 $ (4,804 ) $ — We have adjusted the purchase price allocation to appropriately reflect the liability for the pension funding obligations that we assumed as of the acquisition date, pursuant to the Stock Purchase Agreement. Additionally, we have revised the Consolidated Statements of Cash Flows related to payments made in the second quarter of 2015 to satisfy the pension obligation as well as certain alumina purchases out of investing activities and into operating activities. Pension funding obligations Pursuant to the Stock Purchase Agreement, Alcoa spun-off the pension plan assets for the current and former Mt. Holly employees into a qualified defined benefit plan established by Century. Alcoa and Century agreed to fund their proportionate share of the underfunded Mt. Holly pension plan benefit obligations, measured in accordance with generally accepted accounting principles in the United States ("GAAP") using agreed upon assumptions as of the transaction date. In addition, Century agreed to fund any additional amount needed to bring the Mt. Holly pension benefit obligations to fully funded status on a termination basis under IRS Code Section 414(l) (the "414(l) liability"). In April 2015, Century contributed a total of $34,595 to satisfy its pension plan funding obligations under the Stock Purchase Agreement. The Pension Benefit Guaranty Corporation (the "PBGC") assumptions used for termination basis funding are more conservative than those used for GAAP purposes and resulted in the recognition of a pension asset for the over funded plan. Settlement of amounts due from Alumax Prior to the closing date, the Mt. Holly partnership had amounts due from Alumax for metal off-take, capital, plant administrative, standard cost true-ups and various other costs. These amounts totaling $11,269 were received at closing. The following unaudited pro forma financial information for the three and nine months ended September 30, 2014 reflects our results of continuing operations as if the acquisition of the remaining interest in Mt. Holly had been completed on January 1, 2014. This unaudited pro forma financial information is provided for informational purposes only and is not necessarily indicative of what the actual results of operations would have been had the transactions taken place on January 1, 2014, nor is it indicative of the future consolidated results of operations or financial position of the combined companies. Three months ended September 30, Nine months ended September 30, 2014 2014 Pro forma revenues $ 573,230 $ 1,575,842 Pro forma earnings from continuing operations 58,050 53,824 Pro forma earnings per common share, basic 0.60 0.56 Pro forma earnings per common share, diluted 0.60 0.55 Transactions Recognized Separately from the Mt. Holly acquisition As part of the acquisition, we recognized certain transactions as separate and apart from the business combination with Mt. Holly. The Mt. Holly smelter tolled alumina for its partners and so had no alumina supply of its own. Upon the purchase, we negotiated with Alcoa to purchase $14,880 of alumina inventory under two separate alumina supply agreements. We believe the price paid under these agreements was equivalent to a market rate that would be paid by a market participant. Contract prices were based on published alumina price indexes.

Fair value measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The following section describes the valuation methodology used to measure our financial assets and liabilities that were accounted for at fair value and are categorized based on the fair value hierarchy described in Accounting Standards Codification ("ASC") 820 "Fair Value Measurements and Disclosures." Overview of Century’s valuation methodology Level Significant inputs Cash equivalents 1 Quoted market prices Trust assets (1) 1 Quoted market prices Surety bonds 1 Quoted market prices (1) Trust assets are currently invested in money market funds. These trust assets are held to fund the non-qualified supplemental executive pension benefit obligations for certain of our officers. The trust has sole authority to invest the funds in secure interest producing investments consisting of short-term securities issued or guaranteed by the United States government or cash and cash equivalents. Our fair value measurements include the consideration of market risks that other market participants might consider in pricing the particular asset or liability, specifically non-performance risk and counterparty credit risk. Considerations of the non-performance risk and counterparty credit risk are used to establish the appropriate risk-adjusted discount rates used in our fair value measurements. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. Our assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the valuation of fair value assets and liabilities and the placement within the fair value hierarchy levels. There were no transfers between Level 1 and 2 during the periods presented. There were no transfers into or out of Level 3 during the periods presented. It is our policy to recognize transfers into and transfers out of Level 3 as of the date of the event or change in circumstances that caused the transfer. The following table sets forth our financial assets and liabilities that were accounted for at fair value on a recurring basis by the level of input. Recurring Fair Value Measurements As of September 30, 2015 Level 1 Level 2 Level 3 Total ASSETS: Cash equivalents $ 119,194 $ — $ — $ 119,194 Trust assets 5,998 — — 5,998 Surety bonds 1,870 — — 1,870 TOTAL $ 127,062 $ — $ — $ 127,062 Recurring Fair Value Measurements As of December 31, 2014 Level 1 Level 2 Level 3 Total ASSETS: Cash equivalents $ 137,712 $ — $ — $ 137,712 Trust assets 8,067 — — 8,067 Surety bonds 1,987 — — 1,987 TOTAL $ 147,766 $ — $ — $ 147,766

Earnings (loss) per share

Earnings (loss) per share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings (loss) per share	Earnings (loss) per share Basic earnings (loss) per share ("EPS") amounts are calculated by dividing net income (loss) allocated to common stockholders by the weighted average number of common shares outstanding. Diluted EPS amounts assume the issuance of common stock for all potentially dilutive common shares outstanding. Our Series A Convertible Preferred Stock has similar characteristics to a "participating security" as described by ASC 260 "Earnings Per Share" and we calculate the amount of net income (loss) allocated to common stockholders and basic EPS using the Two-Class Method earnings allocation formula, allocating undistributed income to our preferred stockholder consistent with their participation rights, and diluted EPS using the If-Converted Method when applicable. Our Series A Convertible Preferred Stock is a non-cumulative perpetual participating convertible preferred stock with no set dividend preferences. In periods where we report net losses, we do not allocate these losses to the convertible preferred stock for the computation of basic or diluted EPS. The following table shows the basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2015 and 2014 : For the three months ended September 30, 2015 2014 Loss Shares (000) Per-Share Income Shares (000) Per-Share Net income (loss) $ (56,112 ) $ 50,405 Amount allocated to common stockholders 100.00 % 91.81 % Basic EPS: Net income (loss) allocated to common stockholders (56,112 ) 86,907 $ (0.65 ) 46,277 88,827 $ 0.52 Effect of Dilutive Securities: Share-based compensation plans — — — 705 Diluted EPS: Net income (loss) allocated to common stockholders with assumed conversion $ (56,112 ) 86,907 $ (0.65 ) $ 46,277 89,532 $ 0.52 For the nine months ended September 30, 2015 2014 Loss Shares (000) Per-Share Income Shares (000) Per-Share Net income (loss) $ (16,230 ) $ 50,645 Amount allocated to common stockholders 100.00 % 91.79 % Basic EPS: Net income (loss) allocated to common stockholders (16,230 ) 87,524 $ (0.19 ) 46,487 88,777 $ 0.52 Effect of Dilutive Securities: Share-based compensation plans — — — 595 Diluted EPS: Net income (loss) allocated to common stockholders with assumed conversion $ (16,230 ) 87,524 $ (0.19 ) $ 46,487 89,372 $ 0.52 Securities excluded from the calculation of diluted EPS: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Stock options (1) 317,266 338,433 327,599 344,433 Service-based share awards (1) 646,128 — 599,001 — (1) In periods when we report a net loss, all share awards are excluded from the calculation of diluted weighted average shares outstanding because of their antidilutive effect on earnings (loss) per share. In periods when we report net income, certain option awards may be excluded from the calculation of diluted EPS if the exercise price of the option award was greater than the average market price of the underlying common stock.

Shareholders' equity

Shareholders' equity	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Shareholders' equity	Shareholders’ equity Common Stock Under our Restated Certificate of Incorporation, our Board of Directors is authorized to issue up to 195,000,000 shares of our common stock. The rights, preferences and privileges of holders of our common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of our preferred stock which are currently outstanding, including our Series A Convertible Preferred Stock, or which we may designate and issue in the future. Stock Repurchase Program In August 2011, our Board of Directors approved a $60,000 common stock repurchase program. In 2015, our Board expanded the repurchase program by approving an additional $70,000 , increasing the authorization to repurchase up to $130,000 . From August 2011 through September 30, 2015 , we repurchased 7,186,521 shares of common stock for an aggregate purchase price of $86,276 . There were no share repurchases for the three months ended September 30, 2015 . During the nine months ended September 30, 2015 , we repurchased 2,400,000 shares of common stock for an aggregate purchase price of $36,352 . At September 30, 2015 , we had approximately $43,724 remaining under the repurchase program authorization. The repurchase program may be expanded, suspended or discontinued by our Board, in its sole discretion, at any time. Shares of common stock repurchased are recorded at cost as treasury stock and result in a reduction of shareholders’ equity in the consolidated balance sheets. From time to time, treasury shares may be reissued as contributions to our employee benefit plans and for the conversion of convertible preferred stock. When shares are reissued, we use an average cost method for determining cost. The difference between the cost of the shares and the reissuance price is added to or deducted from additional paid-in capital. Series A Convertible Preferred Stock Glencore holds all of the issued and outstanding Series A Convertible Preferred Stock. The issuance of common stock under our stock incentive programs, debt exchange transactions and any stock offering that excludes Glencore participation triggers anti-dilution provisions of the preferred stock agreement and results in the automatic conversion of Series A Convertible Preferred Stock shares into shares of common stock. The Common and Preferred Stock Activity table below contains additional information about preferred stock conversions during the nine months ended September 30, 2015 and 2014 . Common and Preferred Stock Activity: Preferred stock Common stock (in shares) Series A convertible Treasury Outstanding Beginning balance as of December 31, 2014 78,141 4,786,521 89,064,582 Repurchase of common stock — 2,400,000 (2,400,000 ) Conversion of convertible preferred stock (1,146 ) — 114,524 Issuance for share-based compensation plans — — 152,597 Ending balance as of September 30, 2015 76,995 7,186,521 86,931,703 Beginning balance as of December 31, 2013 79,620 4,786,521 88,710,277 Conversion of convertible preferred stock (950 ) — 95,039 Issuance for share-based compensation plans — — 132,554 Ending balance as of September 30, 2014 78,670 4,786,521 88,937,870

Income taxes

Income taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income taxes	Income taxes We recorded an income tax benefit for the three months ended September 30, 2015 of $2,161 and income tax expense of $12,205 for the nine months ended September 30, 2015 respectively, which primarily consisted of foreign and state income taxes. Our domestic and certain foreign deferred tax assets, net of deferred tax liabilities, are subject to a valuation allowance. We recorded income tax expense for the three and nine months ended September 30, 2014 of $6,444 and $7,004 , respectively, which primarily consisted of foreign and state income taxes. Our income tax benefit or expense is based on an annual effective tax rate forecast, including estimates and assumptions that could change during the year. The application of the requirements for accounting for income taxes in interim periods, after consideration of our valuation allowance, causes a significant variation in the typical relationship between income tax expense and pretax accounting income. As of September 30, 2015 , all of Century's U.S. and certain foreign deferred tax assets, net of deferred tax liabilities, continue to be subject to a valuation allowance.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2015
Inventory, Net [Abstract]
Inventories	Inventories Inventories consist of the following: September 30, 2015 December 31, 2014 Raw materials $ 78,066 $ 78,599 Work-in-process 49,597 33,941 Finished goods 18,412 19,969 Operating and other supplies 152,784 150,971 Total inventories $ 298,859 $ 283,480 Inventories are stated at the lower of cost or market.

Debt

Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Debt	Debt September 30, 2015 December 31, 2014 Debt classified as current liabilities: Hancock County industrial revenue bonds ("IRBs") due 2028, interest payable quarterly (variable interest rates (not to exceed 12%)) (1) $ 7,815 $ 7,815 Debt classified as non-current liabilities: 7.5% senior secured notes due June 1, 2021, net of debt discount of $2,822 and $3,112, respectively, interest payable semiannually 247,178 246,888 Total $ 254,993 $ 254,703 (1) The IRBs are classified as current liabilities because they are remarketed weekly and could be required to be repaid upon demand if there is a failed remarketing. The IRB interest rate at September 30, 2015 was 0.22% . U.S. Revolving Credit Facility General . We and certain of our direct and indirect domestic subsidiaries (collectively, the "Borrowers") and Wells Fargo Capital Finance, LLC, as lender and agent, and Credit Suisse AG and BNP Paribas, as lenders, are parties to an Amended and Restated Loan and Security Agreement, dated May 24, 2013 (as amended, the "U.S. revolving credit facility"). The U.S. revolving credit facility has a term through June 26, 2020 and provides for borrowings of up to $150,000 in the aggregate, including up to $110,000 under a letter of credit sub-facility. Any letters of credit issued and outstanding under the U.S. revolving credit facility reduce our borrowing availability on a dollar-for-dollar basis. The availability of funds under the U.S. revolving credit facility is limited by a specified borrowing base consisting of accounts receivable and inventory of the borrowers which meet the eligibility criteria. Status of our U.S. revolving credit facility: September 30, 2015 Credit facility maximum amount $ 150,000 Borrowing availability, net of outstanding letters of credit 50,026 Outstanding borrowings — Letter of credit sub-facility amount 110,000 Outstanding letters of credit issued 63,005 Guaranty . The Borrowers' obligations under the U.S. revolving credit facility are guaranteed by certain of our domestic subsidiaries and secured by a continuing lien upon and a security interest in all of the Borrowers' accounts receivable, inventory and certain bank accounts. Each Borrower is liable for any and all obligations under the U.S. revolving credit facility on a joint and several basis. Interest Rates and Fees . Any amounts outstanding under the U.S. revolving credit facility will bear interest, at our option, at LIBOR or a base rate, plus, in each case, an applicable interest margin. The applicable interest margin is determined based on the average daily availability for the immediately preceding quarter. In addition, we pay an unused line fee on undrawn amounts, less the amount of our letters of credit exposure. For standby letters of credit, we are required to pay a fee on the face amount of such letters of credit that varies depending on whether the letter of credit exposure is cash collateralized. Covenants . The U.S. revolving credit facility contains customary covenants, including restrictions on mergers and acquisitions, indebtedness, affiliate transactions, liens, dividends and distributions, dispositions of collateral, investments and prepayments of indebtedness, as well as a springing financial covenant that requires the Borrowers to maintain a fixed charge coverage ratio of at least 1.1 to 1.0 any time availability under the U.S. revolving credit facility is less than or equal to $15,000 . As of September 30, 2015 , we were in compliance with all such covenants and our fixed charge coverage ratio was greater than 1.1 to 1.0 . Iceland Revolving Credit Facility General . Nordural Grundartangi ehf ("Grundartangi"), as borrower, and Landsbankinn hf., as lender, entered into a $50,000 Committed Revolving Credit Facility agreement (the "Iceland revolving credit facility"), dated November 27, 2013. Grundartangi may in the future use the Iceland revolving credit facility to repay existing indebtedness or to finance capital expenditures and for ongoing working capital needs and other general corporate purposes. Under the terms of the Iceland revolving credit facility, when Grundartangi borrows funds it will designate a repayment date, which may be any date prior to the maturity of the Iceland revolving credit facility. The Iceland revolving credit facility has a term through November 27, 2016. Status of our Iceland revolving credit facility: September 30, 2015 Credit Facility maximum amount $ 50,000 Borrowing availability 50,000 Outstanding borrowings — Borrowing Base . The availability of funds under the Iceland revolving credit facility is limited by a specified borrowing base consisting of inventory and accounts receivable of Grundartangi. Security . Grundartangi's obligations under the Iceland revolving credit facility are secured by a general bond under which Grundartangi's inventory and accounts receivable are pledged to secure full payment of the loan. Interest Rates and Fees . Any amounts outstanding under the Iceland revolving credit facility will bear interest at LIBOR plus the margin per annum. E.ON contingent obligation The E.ON contingent obligation consists of the aggregate E.ON payments made to Big Rivers Electric Corporation ("Big Rivers") on behalf of Century Kentucky, Inc. ("CAKY") that are in excess of the agreed upon base amount under the long-term cost-based power contract with Kenergy, a member cooperative of Big Rivers (the "Big Rivers Agreement"). Our obligation to make repayments is contingent upon certain operating criteria for Hawesville and the LME price of primary aluminum. When the conditions for repayment are met, and for so long as those conditions continue to be met, we will be obligated to make principal and interest payments, in up to 72 monthly payments . Based on the LME forward market prices for primary aluminum at September 30, 2015 and management's estimate of the LME forward market for periods beyond the quoted periods, we recognized a derivative asset which offsets our contingent obligation. As a result, we recorded a gain of $1,059 and $1,059 in net gain on forward and derivative contracts for the nine months ended September 30, 2015 and 2014 , respectively. In addition, we recorded interest of $(1,059) and $(1,059) in interest expense for the nine months ended September 30, 2015 and 2014 , respectively. In addition, we believe that we will not have any payment obligations for the E.ON contingent obligation through the term of the agreement, which expires in 2028. However, future increases in the LME forward market may result in a partial or full derecognition of the derivative asset and a corresponding recognition of a loss. We classified the E.ON contingent obligation within Level 3 of the fair value hierarchy as its fair value was determined with inputs that are not readily observable in the market. The following table provides information about the balance sheet location and gross amounts offset: Offsetting of financial instruments and derivatives Balance sheet location September 30, 2015 December 31, 2014 E.ON contingent obligation – principal Other liabilities $ (12,902 ) $ (12,902 ) E.ON contingent obligation – accrued interest Other liabilities (6,350 ) (5,291 ) E.ON contingent obligation – derivative asset Other liabilities 19,252 18,193 $ — $ —

Commitments and contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Environmental Contingencies Based upon all available information, we believe our current environmental liabilities do not have, and are not likely to have, a material adverse effect on our financial condition, results of operations or liquidity. However, because of the inherent uncertainties in estimating environmental liabilities primarily due to unknown facts and circumstances and changing governmental regulations and legal standards regarding liability, there can be no assurance that future capital expenditures and costs for environmental compliance at currently or formerly owned or operated properties will not result in liabilities that may have a material adverse effect on our financial condition, results of operations or liquidity. It is our policy to accrue for costs associated with environmental assessments and remedial efforts when it becomes probable that a liability has been incurred and the costs can be reasonably estimated. The aggregate environmental-related accrued liabilities were $ 1,419 and $ 1,101 at September 30, 2015 and December 31, 2014 , respectively. All accrued amounts have been recorded without giving effect to any possible future recoveries. With respect to costs for ongoing environmental compliance, including maintenance and monitoring, such costs are expensed as incurred. In July 2006, we were named as a defendant, together with certain affiliates of Alcan Inc., in a lawsuit brought by Alcoa Inc. seeking to determine responsibility for certain environmental indemnity obligations related to the sale of a cast aluminum plate manufacturing facility located in Vernon, California, which we purchased from Alcoa Inc. in December 1998, and sold to Alcan Rolled Products-Ravenswood LLC in July 1999. The complaint also seeks costs and attorney fees. The matter is in a preliminary stage in the U.S. District Court for the District of Delaware, and we cannot predict the ultimate outcome of this action or estimate a range of possible losses related to this matter at this time. Matters relating to the St. Croix Alumina Refining Facility We are a party to a United States Environmental Protection Agency Administrative Order on Consent (the "Order") pursuant to which certain past and present owners of an alumina refining facility at St. Croix, Virgin Islands (the "St. Croix Alumina Refinery") have agreed to carry out a Hydrocarbon Recovery Plan to remove and manage hydrocarbons floating on groundwater underlying the facility. Pursuant to the Hydrocarbon Recovery Plan, recovered hydrocarbons and groundwater are delivered to the adjacent petroleum refinery where they are received and managed. In connection with the sale of the facility by Lockheed Martin Corporation ("Lockheed") to one of our affiliates, Virgin Islands Alumina Corporation ("Vialco"), in 1989, Lockheed, Vialco and Century entered into the Lockheed-Vialco Asset Purchase Agreement. The indemnity provisions contained in the Lockheed-Vialco Asset Purchase Agreement allocate responsibility for certain environmental matters. Lockheed has tendered indemnity to Vialco. We have likewise tendered indemnity to Lockheed. Through September 30, 2015 , we have expended approximately $ 1,085 on the Hydrocarbon Recovery Plan. At this time, we are not able to estimate the amount of any future potential payments under this indemnification to comply with the Order, but we do not anticipate that any such amounts will have a material adverse effect on our financial condition, results of operations or liquidity, regardless of the final outcome. Vialco sold the St. Croix Alumina Refinery to St. Croix Alumina, LLC, a subsidiary of Alcoa in 1995. In December 2010, Century was among several defendants named in a lawsuit filed by plaintiffs who either worked, resided or owned property in the area downwind from the St. Croix Alumina Refinery. In March 2011, Century was also named a defendant in a nearly identical suit brought by certain additional plaintiffs. The plaintiffs in both suits allege damages caused by the presence of red mud and other particulates coming from the alumina facility and are seeking unspecified monetary damages, costs and attorney fees as well as certain injunctive relief. We tendered indemnity and defense to St. Croix Alumina LLC and Alcoa Alumina & Chemical LLC under the terms of an acquisition agreement relating to the facility and have filed motions to dismiss plaintiffs’ claims. In August 2015, the Superior Court of the Virgin Islands, Division of St. Croix denied the motions to dismiss but ordered all plaintiffs to refile individual complaints. At this time, it is not practicable to predict the ultimate outcome of or to estimate a range of possible losses for any of the foregoing actions relating to the St. Croix Alumina Refinery. Legal Contingencies In addition to the foregoing matters, we have pending against us or may be subject to various lawsuits, claims and proceedings related primarily to employment, commercial, stockholder, safety and health matters. While the results of such litigation matters and claims cannot be predicted with certainty, we believe that the final outcome of such matters will not have a material adverse impact on our financial position or results of operations. However, because of the nature and inherent uncertainties of litigation, should the outcome of these actions be unfavorable, our business, financial condition, and results of operations could be materially and adversely affected. In evaluating whether to accrue for losses associated with legal contingencies, it is our policy to take into consideration factors such as the facts and circumstances asserted, our historical experience with contingencies of a similar nature, the likelihood of our prevailing and the severity of any potential loss. For some matters, no accrual is established because we have assessed our risk of loss to be remote. Where the risk of loss is probable and the amount of the loss can be reasonably estimated, we record an accrual, either on an individual basis or with respect to a group of matters involving similar claims, based on the factors set forth above. When we have assessed that a loss associated with legal contingencies is reasonably possible, we determine if estimates of possible losses or ranges of possible losses are in excess of related accrued liabilities, if any. Based on current knowledge, management has ascertained estimates for losses that are reasonably possible and management does not believe that any reasonably possible outcomes in excess of our accruals, if any, either individually or in aggregate, would be material to our financial condition, results of operations, or liquidity. We reevaluate and update our assessments and accruals as matters progress over time. Ravenswood Retiree Medical Benefits changes In November 2009, Century Aluminum of West Virginia ("CAWV") filed a class action complaint for declaratory judgment against the United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union ("USW"), the USW’s local and certain CAWV retirees, individually and as class representatives, seeking a declaration of CAWV’s rights to modify/terminate retiree medical benefits. Later in November 2009, the USW and representatives of a retiree class filed a separate suit against CAWV, Century Aluminum Company, Century Aluminum Master Welfare Benefit Plan, and various John Does with respect to the foregoing. These actions, entitled Dewhurst, et al. v. Century Aluminum Co., et al., and Century Aluminum of West Virginia, Inc. v. United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union, AFL-CIO/CLC, et al., have been consolidated and venue has been set in the District Court for the Southern District of West Virginia. In January 2010, the USW filed a motion for preliminary injunction to prevent us from implementing any modifications to the retiree medical benefits while these lawsuits are pending, which was dismissed by the trial court, and affirmed upon appeal. CAWV filed a motion for summary judgment of these actions which motion was granted on September 9, 2015. The decision of the court is currently being appealed by the USW to the Court of Appeals for the 4th Circuit. PBGC Settlement In June 2011, the PBGC informed us that it believed a "cessation of operations" under ERISA had occurred at our Ravenswood facility as a result of the curtailment of operations at the facility. Although we disagree that a "cessation of operations" occurred, we entered into a settlement agreement with the PBGC in April 2013 to resolve the matter. Pursuant to the terms of the agreement, we will make additional contributions (above any minimum required contributions) to our defined benefit pension plans totaling approximately $ 17,400 over the term of the agreement. During 2013, we made contributions pursuant to this agreement of approximately $6,700 . Under certain circumstances, in periods of lower primary aluminum prices relative to our cost of operations, we may defer one or more of these payments, but we would be required to provide the PBGC with acceptable security for any deferred payments. We elected to defer contributions for 2014 and 2015 under the PBGC agreement and have provided the PBGC with the appropriate security. In March 2015, we made a prepayment of the deferred PBGC contributions of $1,076 . Power Commitments and Contingencies Hawesville Hawesville has a power supply arrangement with Kenergy and EDF Trading North America, LLC (“EDF") which provides market-based power to the Hawesville smelter. Under this arrangement, the power companies purchase power on the open market and pass it through to Hawesville at Midcontinent Independent System Operator ("MISO") pricing plus transmission and other costs. The power supply arrangement with Kenergy has an effective term through December 2023. The arrangement with EDF to act as our market participant with MISO has an effective term through May 2017, extending year to year thereafter unless a one year notice is given. Sebree Sebree has a power supply arrangement with Kenergy and EDF which provides market-based power to the Sebree smelter. Similar to the arrangement at Hawesville, the power companies purchase power on the open market and pass it through to Sebree at MISO pricing plus transmission and other costs. The power supply arrangement with Kenergy has an effective term through December 2023. The arrangement with EDF to act as our market participant with MISO has an effective term through May 2017, extending year to year thereafter unless a one year notice is given. Mt. Holly Mt. Holly has a power purchase agreement (the "Santee Cooper Agreement") with the South Carolina Public Service Authority ("Santee Cooper") with an effective term through December 2015. The Santee Cooper Agreement provides power for Mt. Holly’s full production capacity requirements at prices based on published rate schedules (which are subject to change), with adjustments for fuel prices and other items. The Santee Cooper Agreement restricts Mt. Holly’s ability to reduce its power consumption (or the associated payment obligations) below contracted levels. On October 22, 2015, we issued a notice to employees at our Mt. Holly, South Carolina aluminum smelter of our intent to curtail the Mt. Holly plant operations by no later than December 31, 2015, when our current power contract at Mt. Holly expires, if we are unable to secure a competitively priced power arrangement to deliver energy to the plant. The announcement was made pursuant to the federal Working Adjustment and Retraining Notification Act (WARN). Grundartangi Grundartangi has power purchase agreements with HS Orka hf ("HS"), Landsvirkjun and Orkuveita Reykjavikur ("OR") to provide power to its Grundartangi smelter. These power purchase agreements, which will expire on various dates from 2019 through 2036 (subject to extension), provide power at LME-based variable rates. Each power purchase agreement contains take-or-pay obligations with respect to a significant percentage of the total committed and available power under such agreement. In June 2012, Grundartangi entered into a supplemental power contract with Landsvirkjun. The supplemental power contract, which will expire in October 2029 (or upon the occurrence of certain earlier events), will provide Grundartangi with supplemental power, as Grundartangi may request from time to time, at LME-based variable rates. Grundartangi has agreed to make certain prepayments to Landsvirkjun for power expected to be used at a later date in connection with the contract, which will reduce the price paid for power at the time of consumption. As of September 30, 2015 , these power prepayments totaled approximately $1,792 . Helguvik Nordural Helguvik ehf ("Helguvik") has power purchase agreements with HS and OR to provide power to the Helguvik project. These power purchase agreements provide power at LME-based variable rates and contain take-or-pay obligations with respect to a significant percentage of the total committed and available power under such agreements. The power purchase agreements contain certain conditions to HS’s and OR’s obligations. HS and OR have alleged that certain of these conditions have not been satisfied. The first stage of power under the OR power purchase agreement (approximately 47.5 MW) became available in the fourth quarter of 2011 and is currently being utilized at Grundartangi. In July 2014, HS commenced arbitration proceedings against Helguvik seeking, among other things, an order declaring, (i) that the conditions to the power contract have not been fulfilled and, (ii) that the power contract is therefore no longer valid. Helguvik believes HS' renewed claims are without merit and intends to defend itself against them. Helguvik is in discussions with OR with respect to such conditions and other matters pertaining to these agreements. In June 2014, Helguvik entered into a supplemental power contract with OR. The supplemental power contract will expire in October 2036 (or upon the occurrence of certain earlier events) and will provide Grundartangi or Helguvik with supplemental power at LME-based rates, as may be requested from Grundartangi or Helguvik from time to time. Other Commitments and Contingencies Labor Commitments The bargaining unit employees at our Grundartangi, Vlissingen, Hawesville, Sebree and Ravenswood facilities are represented by labor unions, representing 59% of our total workforce. 81% of Grundartangi’s work force is represented by five labor unions, governed by a labor agreement that establishes wages and work rules for covered employees. A new agreement was entered into in March 2015 and is effective through December 31, 2019. 80% of Vlissingen's work force is represented by the Federation for the Metal and Electrical Industry ("FME"), governed by a labor agreement that expired on May 1, 2015. Since such time, we have been operating under the terms of the expired agreement while we engage in negotiations with the FME regarding the terms of a new agreement. The FME negotiates working conditions with trade unions on behalf of its members. 53% of our U.S. based work force is represented by the USW. In June 2015, CAKY entered into a new collective bargaining agreement with the USW for its employees at the CAKY smelter. The agreement is effective through April 1, 2020. In July 2014, Century Sebree entered into a new collective bargaining agreement with the USW for its employees at the Sebree smelter. The agreement is effective through October 28, 2019. The labor agreement for CAWV’s Ravenswood plant employees represented by the USW expired on August 31, 2010.

Forward delivery contracts and

Forward delivery contracts and financial instruments	9 Months Ended
	Sep. 30, 2015
Forward Delivery Contracts and Financial Instruments [Abstract]
Forward delivery contracts and financial instruments	Forward delivery contracts and financial instruments As a producer of primary aluminum, we are exposed to fluctuating raw material and primary aluminum prices. From time to time we enter into fixed and market priced contracts for the sale of primary aluminum and the purchase of raw materials in future periods. Forward Physical Delivery Agreements Primary Aluminum Sales and Tolling Contracts Contract Customer Volume Term Pricing Glencore Grundartangi Metal Agreement Glencore All primary aluminum produced at Grundartangi, net of tolling and other sales commitments January 1, 2014 through December 31, 2017 Variable, based on LME and European Duty Paid premium Glencore U.S. Aluminum Sales Agreement Glencore Substantially all of the primary aluminum produced in North America January 1, 2015 through December 31, 2016 Variable, based on LME and Midwest premium and product premiums, as applicable Glencore Toll Agreement Glencore 90,000 tonnes per year ("tpy") Through July 2016 Variable, based on LME and European Duty Paid premium Apart from the Glencore Grundartangi Metal Agreement, the Glencore U.S. Aluminum Sales Agreement and the Southwire Metal Agreement (which expired at the end of 2014), we had the following forward delivery contractual commitments: Other forward delivery contracts September 30, 2015 December 31, 2014 (in tonnes) Other forward delivery contracts – total 6,486 6,108 Other forward delivery contracts – Glencore — 4,058 We had no significant outstanding primary aluminum forward financial sales contracts or significant fixed price forward financial contracts to purchase aluminum at September 30, 2015 .

Supplemental cash flow informat

Supplemental cash flow information	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental cash flow information	Supplemental cash flow information Nine months ended September 30, 2015 2014 Cash paid for: Interest $ 9,396 $ 9,684 Income/withholding taxes (1) 13,921 10,079 Non-cash investing activities: Accrued capital costs $ 2,155 $ 663 (1) We paid withholding taxes of $8,388 and $5,491 in Iceland on intercompany dividends during the nine months ended September 30, 2015 and 2014 , respectively. Our tax payments in Iceland for withholding taxes, income taxes and any associated refunds are denominated in Icelandic kronur ("ISK"). In April 2015, we issued shares of common stock to certain employees to settle performance unit liabilities, net of withholding taxes of $1,516 .

Asset retirement obligations (_

Asset retirement obligations (“ARO”)	9 Months Ended
	Sep. 30, 2015
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligations (“ARO”)	Asset retirement obligations ("ARO") Our asset retirement obligations consist primarily of costs associated with the disposal of spent pot liner used in the reduction cells of our domestic facilities. The reconciliation of the changes in the asset retirement obligations is presented below: Nine months ended September 30, 2015 Year ended December 31, 2014 Beginning balance, ARO liability $ 36,950 $ 27,113 Additional ARO liability incurred 3,723 2,548 ARO liabilities settled (5,206 ) (4,731 ) Accretion expense 1,360 1,517 Adjustments (1,886 ) — ARO liability from Mt. Holly acquisition — 10,503 Ending balance, ARO liability $ 34,941 $ 36,950 Certain conditional AROs related to the disposal costs of fixed assets at our primary aluminum facilities have not been recorded because they have an indeterminate settlement date and will be initially recognized in the period in which sufficient information exists to estimate their fair value.

Components of accumulated other

Components of accumulated other comprehensive loss	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Components of accumulated other comprehensive loss	Components of accumulated other comprehensive loss September 30, 2015 December 31, 2014 Defined benefit plan liabilities $ (111,560 ) $ (128,664 ) Unrealized loss on financial instruments (1,389 ) (1,249 ) Other comprehensive loss before income tax effect (112,949 ) (129,913 ) Income tax effect (1) 11,083 12,231 Accumulated other comprehensive loss $ (101,866 ) $ (117,682 ) (1) The allocation of the income tax effect to the components of other comprehensive income is as follows: September 30, 2015 December 31, 2014 Defined benefit plan liabilities $ 11,639 $ 12,812 Unrealized loss on financial instruments (556 ) (581 ) The following table summarizes the changes in the accumulated balances for each component of accumulated other comprehensive loss ("AOCI"): Defined benefit plan and other postretirement liabilities Equity in investee other comprehensive income Unrealized loss on financial instruments Total, net of tax Balance, July 1, 2015 $ (96,335 ) $ — $ (1,907 ) $ (98,242 ) Other comprehensive income before reclassifications (4,114 ) — — (4,114 ) Net amount reclassified to net loss 529 — (39 ) 490 Balance, September 30, 2015 $ (99,920 ) $ — $ (1,946 ) $ (101,866 ) Balance, July 1, 2014 $ (77,843 ) $ (12,266 ) $ (1,755 ) $ (91,864 ) Other comprehensive income (loss) before reclassifications — (17 ) — (17 ) Net amount reclassified to net income (98 ) — (38 ) (136 ) Balance, September 30, 2014 $ (77,941 ) $ (12,283 ) $ (1,793 ) $ (92,017 ) Balance, December 31, 2014 $ (115,852 ) $ — $ (1,830 ) $ (117,682 ) Other comprehensive income before reclassifications (1) 13,928 — — 13,928 Net amount reclassified to net income 2,004 — (116 ) 1,888 Balance, September 30, 2015 $ (99,920 ) $ — $ (1,946 ) $ (101,866 ) Balance, December 31, 2013 $ (77,921 ) $ (12,232 ) $ (1,679 ) $ (91,832 ) Other comprehensive income (loss) before reclassifications 440 (51 ) — 389 Net amount reclassified to net loss (460 ) — (114 ) (574 ) Balance, September 30, 2014 $ (77,941 ) $ (12,283 ) $ (1,793 ) $ (92,017 ) (1) The gain in other comprehensive income before reclassifications is due to a plan remeasurement related to our labor negotiations, census and other actuarial adjustments. Reclassifications out of AOCI were included in the consolidated statements of operations as follows: For the three months ended September 30, For the nine months ended September 30, AOCI Components Location 2015 2014 2015 2014 Defined benefit plan and other postretirement liabilities Cost of goods sold $ 669 $ 308 $ 2,422 $ 924 Selling, general and administrative expenses 252 142 755 427 Income tax expense (392 ) (548 ) (1,173 ) (1,811 ) Net of tax $ 529 $ (98 ) $ 2,004 $ (460 ) Unrealized loss on financial instruments Cost of goods sold $ (47 ) $ (46 ) $ (140 ) $ (139 ) Income tax expense 8 8 24 25 Net of tax $ (39 ) $ (38 ) $ (116 ) $ (114 )

Components of net periodic bene

Components of net periodic benefit cost	9 Months Ended
	Sep. 30, 2015
Components of net periodic benefit cost [Abstract]
Components of net periodic benefit cost	Components of net periodic benefit cost Pension Benefits Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Service cost $ 2,074 $ 1,333 $ 5,287 $ 3,999 Interest cost 3,348 2,871 10,003 8,612 Expected return on plan assets (5,262 ) (3,550 ) (16,025 ) (10,648 ) Amortization of prior service costs 28 9 83 27 Amortization of net loss 1,025 477 3,049 1,430 Curtailment 377 — 365 — Net periodic benefit cost $ 1,590 $ 1,140 $ 2,762 $ 3,420 Other Postretirement Benefits ("OPEB") Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Service cost $ 468 $ 397 $ 1,517 $ 1,191 Interest cost 1,542 1,603 4,523 4,809 Amortization of prior service cost (1,007 ) (961 ) (2,929 ) (2,883 ) Amortization of net loss 874 925 2,973 2,777 Net periodic benefit cost $ 1,877 $ 1,964 $ 6,084 $ 5,894 Employer contributions During the nine months ended September 30, 2015 , we made contributions of $3,551 to the qualified defined benefit plans we sponsor.

Subsequent events

Subsequent events	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent events	Subsequent events On October 22, 2015, we issued a notice to employees at our Mt. Holly, South Carolina aluminum smelter of our intent to curtail the Mt. Holly plant operations by no later than December 31, 2015, when our current power contract at Mt. Holly expires, if we are unable to secure a competitively priced power arrangement to deliver energy to the plant. The announcement was made pursuant to the federal Working Adjustment and Retraining Notification Act (WARN). On October 30, 2015, we issued a notice to employees at our Sebree, Kentucky aluminum smelter of our intent to curtail one of its three potlines by December 31, 2015. The announcement was made pursuant to WARN.

Fair value measurements (Polici

Fair value measurements (Policies)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Transfer, Policy	It is our policy to recognize transfers into and transfers out of Level 3 as of the date of the event or change in circumstances that caused the transfer.

Related party transactions (Tab

Related party transactions (Tables)	9 Months Ended
	Sep. 30, 2015
Related Party Transactions [Abstract]
Schedule of related party transactions	A summary of the significant related party transactions for the three and nine months ended September 30, 2015 and 2014 is as follows: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Net sales to Glencore $ 428,018 $ 324,775 $ 1,517,428 $ 898,931 Purchases from Glencore 86,664 69,256 328,120 194,111 Purchases from BHH 13,515 10,715 41,768 38,438

Business acquisitions (Tables)

Business acquisitions (Tables)	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Summary of consideration transferred	The following table summarizes all of the elements of consideration for the transaction, including the preliminary estimated fair value of contingent consideration. Preliminary as of December 1, 2014 Purchase price $ 67,500 Contingent consideration 13,780 Economic, working capital and other closing adjustments (13,513 ) Total consideration transferred $ 67,767
Schedule of purchase price allocation	The following purchase price allocation is preliminary and subject to change based on the finalization of the valuation of acquired assets and liabilities. Preliminary estimate of the acquisition date fair value as of December 1, 2014 Measurement period adjustments Adjusted preliminary estimate of the acquisition date fair value as of December 1, 2014 Assets Acquired: Inventories $ 26,105 $ (2,126 ) $ 23,979 Due from Alumax 20,786 (9,517 ) 11,269 Prepaid and other current assets 2,527 — 2,527 Intangible asset 2,580 — 2,580 Pension asset 30,842 — 30,842 Property, plant and equipment – net 127,089 15,748 142,837 Total assets acquired $ 209,929 $ 4,105 $ 214,034 Liabilities Assumed: Accounts payable, trade $ 41,471 $ — $ 41,471 Accrued and other current liabilities 8,335 255 8,590 Accrued pension benefit costs — 34,595 34,595 Accrued postretirement benefit costs 2,857 — 2,857 Asset retirement obligations 8,213 — 8,213 Deferred taxes 4,804 (2,118 ) 2,686 Total liabilities assumed $ 65,680 $ 32,732 $ 98,412 Goodwill $ 4,804 $ (4,804 ) $ —
Acquisitions, pro forma information	The following unaudited pro forma financial information for the three and nine months ended September 30, 2014 reflects our results of continuing operations as if the acquisition of the remaining interest in Mt. Holly had been completed on January 1, 2014. This unaudited pro forma financial information is provided for informational purposes only and is not necessarily indicative of what the actual results of operations would have been had the transactions taken place on January 1, 2014, nor is it indicative of the future consolidated results of operations or financial position of the combined companies. Three months ended September 30, Nine months ended September 30, 2014 2014 Pro forma revenues $ 573,230 $ 1,575,842 Pro forma earnings from continuing operations 58,050 53,824 Pro forma earnings per common share, basic 0.60 0.56 Pro forma earnings per common share, diluted 0.60 0.55

Fair value measurements (Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of valuation methodology for assets and liabilities at fair value	The following section describes the valuation methodology used to measure our financial assets and liabilities that were accounted for at fair value and are categorized based on the fair value hierarchy described in Accounting Standards Codification ("ASC") 820 "Fair Value Measurements and Disclosures." Overview of Century’s valuation methodology Level Significant inputs Cash equivalents 1 Quoted market prices Trust assets (1) 1 Quoted market prices Surety bonds 1 Quoted market prices (1) Trust assets are currently invested in money market funds. These trust assets are held to fund the non-qualified supplemental executive pension benefit obligations for certain of our officers. The trust has sole authority to invest the funds in secure interest producing investments consisting of short-term securities issued or guaranteed by the United States government or cash and cash equivalents.
Financial assets and liabilities at fair value on a recurring basis	The following table sets forth our financial assets and liabilities that were accounted for at fair value on a recurring basis by the level of input. Recurring Fair Value Measurements As of September 30, 2015 Level 1 Level 2 Level 3 Total ASSETS: Cash equivalents $ 119,194 $ — $ — $ 119,194 Trust assets 5,998 — — 5,998 Surety bonds 1,870 — — 1,870 TOTAL $ 127,062 $ — $ — $ 127,062 Recurring Fair Value Measurements As of December 31, 2014 Level 1 Level 2 Level 3 Total ASSETS: Cash equivalents $ 137,712 $ — $ — $ 137,712 Trust assets 8,067 — — 8,067 Surety bonds 1,987 — — 1,987 TOTAL $ 147,766 $ — $ — $ 147,766

Earnings (loss) per share (Tabl

Earnings (loss) per share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Basic and diluted earnings (loss) per share	The following table shows the basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2015 and 2014 : For the three months ended September 30, 2015 2014 Loss Shares (000) Per-Share Income Shares (000) Per-Share Net income (loss) $ (56,112 ) $ 50,405 Amount allocated to common stockholders 100.00 % 91.81 % Basic EPS: Net income (loss) allocated to common stockholders (56,112 ) 86,907 $ (0.65 ) 46,277 88,827 $ 0.52 Effect of Dilutive Securities: Share-based compensation plans — — — 705 Diluted EPS: Net income (loss) allocated to common stockholders with assumed conversion $ (56,112 ) 86,907 $ (0.65 ) $ 46,277 89,532 $ 0.52 For the nine months ended September 30, 2015 2014 Loss Shares (000) Per-Share Income Shares (000) Per-Share Net income (loss) $ (16,230 ) $ 50,645 Amount allocated to common stockholders 100.00 % 91.79 % Basic EPS: Net income (loss) allocated to common stockholders (16,230 ) 87,524 $ (0.19 ) 46,487 88,777 $ 0.52 Effect of Dilutive Securities: Share-based compensation plans — — — 595 Diluted EPS: Net income (loss) allocated to common stockholders with assumed conversion $ (16,230 ) 87,524 $ (0.19 ) $ 46,487 89,372 $ 0.52
Securities excluded from the calculation of diluted EPS	Securities excluded from the calculation of diluted EPS: Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Stock options (1) 317,266 338,433 327,599 344,433 Service-based share awards (1) 646,128 — 599,001 — (1) In periods when we report a net loss, all share awards are excluded from the calculation of diluted weighted average shares outstanding because of their antidilutive effect on earnings (loss) per share. In periods when we report net income, certain option awards may be excluded from the calculation of diluted EPS if the exercise price of the option award was greater than the average market price of the underlying common stock.

Shareholders' equity (Tables)

Shareholders' equity (Tables)	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Common and Preferred Stock Activity	The Common and Preferred Stock Activity table below contains additional information about preferred stock conversions during the nine months ended September 30, 2015 and 2014 . Common and Preferred Stock Activity: Preferred stock Common stock (in shares) Series A convertible Treasury Outstanding Beginning balance as of December 31, 2014 78,141 4,786,521 89,064,582 Repurchase of common stock — 2,400,000 (2,400,000 ) Conversion of convertible preferred stock (1,146 ) — 114,524 Issuance for share-based compensation plans — — 152,597 Ending balance as of September 30, 2015 76,995 7,186,521 86,931,703 Beginning balance as of December 31, 2013 79,620 4,786,521 88,710,277 Conversion of convertible preferred stock (950 ) — 95,039 Issuance for share-based compensation plans — — 132,554 Ending balance as of September 30, 2014 78,670 4,786,521 88,937,870

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2015
Inventory, Net [Abstract]
Schedule of Inventories	Inventories consist of the following: September 30, 2015 December 31, 2014 Raw materials $ 78,066 $ 78,599 Work-in-process 49,597 33,941 Finished goods 18,412 19,969 Operating and other supplies 152,784 150,971 Total inventories $ 298,859 $ 283,480

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of Debt	September 30, 2015 December 31, 2014 Debt classified as current liabilities: Hancock County industrial revenue bonds ("IRBs") due 2028, interest payable quarterly (variable interest rates (not to exceed 12%)) (1) $ 7,815 $ 7,815 Debt classified as non-current liabilities: 7.5% senior secured notes due June 1, 2021, net of debt discount of $2,822 and $3,112, respectively, interest payable semiannually 247,178 246,888 Total $ 254,993 $ 254,703 (1) The IRBs are classified as current liabilities because they are remarketed weekly and could be required to be repaid upon demand if there is a failed remarketing. The IRB interest rate at September 30, 2015 was 0.22% .
Schedule of Line of Credit Facilities	Status of our U.S. revolving credit facility: September 30, 2015 Credit facility maximum amount $ 150,000 Borrowing availability, net of outstanding letters of credit 50,026 Outstanding borrowings — Letter of credit sub-facility amount 110,000 Outstanding letters of credit issued 63,005 Status of our Iceland revolving credit facility: September 30, 2015 Credit Facility maximum amount $ 50,000 Borrowing availability 50,000 Outstanding borrowings —
Offsetting of financial instruments and derivatives	The following table provides information about the balance sheet location and gross amounts offset: Offsetting of financial instruments and derivatives Balance sheet location September 30, 2015 December 31, 2014 E.ON contingent obligation – principal Other liabilities $ (12,902 ) $ (12,902 ) E.ON contingent obligation – accrued interest Other liabilities (6,350 ) (5,291 ) E.ON contingent obligation – derivative asset Other liabilities 19,252 18,193 $ — $ —

Forward delivery contracts an32

Forward delivery contracts and financial instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Forward Delivery Contracts and Financial Instruments [Abstract]
Schedule of Forward Physical Delivery Agreements	Forward Physical Delivery Agreements Primary Aluminum Sales and Tolling Contracts Contract Customer Volume Term Pricing Glencore Grundartangi Metal Agreement Glencore All primary aluminum produced at Grundartangi, net of tolling and other sales commitments January 1, 2014 through December 31, 2017 Variable, based on LME and European Duty Paid premium Glencore U.S. Aluminum Sales Agreement Glencore Substantially all of the primary aluminum produced in North America January 1, 2015 through December 31, 2016 Variable, based on LME and Midwest premium and product premiums, as applicable Glencore Toll Agreement Glencore 90,000 tonnes per year ("tpy") Through July 2016 Variable, based on LME and European Duty Paid premium Apart from the Glencore Grundartangi Metal Agreement, the Glencore U.S. Aluminum Sales Agreement and the Southwire Metal Agreement (which expired at the end of 2014), we had the following forward delivery contractual commitments: Other forward delivery contracts September 30, 2015 December 31, 2014 (in tonnes) Other forward delivery contracts – total 6,486 6,108 Other forward delivery contracts – Glencore — 4,058

Supplemental cash flow inform33

Supplemental cash flow information (Tables)	9 Months Ended
	Sep. 30, 2015
Supplemental Cash Flow Information [Abstract]
Supplemental cash flow information	Nine months ended September 30, 2015 2014 Cash paid for: Interest $ 9,396 $ 9,684 Income/withholding taxes (1) 13,921 10,079 Non-cash investing activities: Accrued capital costs $ 2,155 $ 663 (1) We paid withholding taxes of $8,388 and $5,491 in Iceland on intercompany dividends during the nine months ended September 30, 2015 and 2014 , respectively. Our tax payments in Iceland for withholding taxes, income taxes and any associated refunds are denominated in Icelandic kronur ("ISK").

Asset retirement obligations 34

Asset retirement obligations (“ARO”) (Tables)	9 Months Ended
	Sep. 30, 2015
Asset Retirement Obligation Disclosure [Abstract]
Schedule of changes in asset retirement obligations	The reconciliation of the changes in the asset retirement obligations is presented below: Nine months ended September 30, 2015 Year ended December 31, 2014 Beginning balance, ARO liability $ 36,950 $ 27,113 Additional ARO liability incurred 3,723 2,548 ARO liabilities settled (5,206 ) (4,731 ) Accretion expense 1,360 1,517 Adjustments (1,886 ) — ARO liability from Mt. Holly acquisition — 10,503 Ending balance, ARO liability $ 34,941 $ 36,950

Components of accumulated oth35

Components of accumulated other comprehensive loss (Tables)	9 Months Ended
	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated balances for each component of AOCI	September 30, 2015 December 31, 2014 Defined benefit plan liabilities $ (111,560 ) $ (128,664 ) Unrealized loss on financial instruments (1,389 ) (1,249 ) Other comprehensive loss before income tax effect (112,949 ) (129,913 ) Income tax effect (1) 11,083 12,231 Accumulated other comprehensive loss $ (101,866 ) $ (117,682 ) (1) The allocation of the income tax effect to the components of other comprehensive income is as follows: September 30, 2015 December 31, 2014 Defined benefit plan liabilities $ 11,639 $ 12,812 Unrealized loss on financial instruments (556 ) (581 ) The following table summarizes the changes in the accumulated balances for each component of accumulated other comprehensive loss ("AOCI"): Defined benefit plan and other postretirement liabilities Equity in investee other comprehensive income Unrealized loss on financial instruments Total, net of tax Balance, July 1, 2015 $ (96,335 ) $ — $ (1,907 ) $ (98,242 ) Other comprehensive income before reclassifications (4,114 ) — — (4,114 ) Net amount reclassified to net loss 529 — (39 ) 490 Balance, September 30, 2015 $ (99,920 ) $ — $ (1,946 ) $ (101,866 ) Balance, July 1, 2014 $ (77,843 ) $ (12,266 ) $ (1,755 ) $ (91,864 ) Other comprehensive income (loss) before reclassifications — (17 ) — (17 ) Net amount reclassified to net income (98 ) — (38 ) (136 ) Balance, September 30, 2014 $ (77,941 ) $ (12,283 ) $ (1,793 ) $ (92,017 ) Balance, December 31, 2014 $ (115,852 ) $ — $ (1,830 ) $ (117,682 ) Other comprehensive income before reclassifications (1) 13,928 — — 13,928 Net amount reclassified to net income 2,004 — (116 ) 1,888 Balance, September 30, 2015 $ (99,920 ) $ — $ (1,946 ) $ (101,866 ) Balance, December 31, 2013 $ (77,921 ) $ (12,232 ) $ (1,679 ) $ (91,832 ) Other comprehensive income (loss) before reclassifications 440 (51 ) — 389 Net amount reclassified to net loss (460 ) — (114 ) (574 ) Balance, September 30, 2014 $ (77,941 ) $ (12,283 ) $ (1,793 ) $ (92,017 ) (1) The gain in other comprehensive income before reclassifications is due to a plan remeasurement related to our labor negotiations, census and other actuarial adjustments.
Reclassification out of AOCI	Reclassifications out of AOCI were included in the consolidated statements of operations as follows: For the three months ended September 30, For the nine months ended September 30, AOCI Components Location 2015 2014 2015 2014 Defined benefit plan and other postretirement liabilities Cost of goods sold $ 669 $ 308 $ 2,422 $ 924 Selling, general and administrative expenses 252 142 755 427 Income tax expense (392 ) (548 ) (1,173 ) (1,811 ) Net of tax $ 529 $ (98 ) $ 2,004 $ (460 ) Unrealized loss on financial instruments Cost of goods sold $ (47 ) $ (46 ) $ (140 ) $ (139 ) Income tax expense 8 8 24 25 Net of tax $ (39 ) $ (38 ) $ (116 ) $ (114 )

Components of net periodic be36

Components of net periodic benefit cost (Tables)	9 Months Ended
	Sep. 30, 2015
Components of net periodic benefit cost [Abstract]
Schedule of net periodic benefit cost	Pension Benefits Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Service cost $ 2,074 $ 1,333 $ 5,287 $ 3,999 Interest cost 3,348 2,871 10,003 8,612 Expected return on plan assets (5,262 ) (3,550 ) (16,025 ) (10,648 ) Amortization of prior service costs 28 9 83 27 Amortization of net loss 1,025 477 3,049 1,430 Curtailment 377 — 365 — Net periodic benefit cost $ 1,590 $ 1,140 $ 2,762 $ 3,420 Other Postretirement Benefits ("OPEB") Three months ended September 30, Nine months ended September 30, 2015 2014 2015 2014 Service cost $ 468 $ 397 $ 1,517 $ 1,191 Interest cost 1,542 1,603 4,523 4,809 Amortization of prior service cost (1,007 ) (961 ) (2,929 ) (2,883 ) Amortization of net loss 874 925 2,973 2,777 Net periodic benefit cost $ 1,877 $ 1,964 $ 6,084 $ 5,894

Ravenswood impairment (Details)

Ravenswood impairment (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Ravenswood impairment		$ 0	$ 0	$ 30,850	$ 0
Write-down of inventory				31,013	$ (1,247)
Assets held for disposal		32,067		32,067		$ 0
Employee Severance and Postemployment Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Expected restructuring cost	$ 1,550
Ravenswood Aluminum Smelter [Member]
Restructuring Cost and Reserve [Line Items]
Ravenswood impairment	30,850
Impairment of assets	21,500
Write-down of inventory	$ 7,800
Assets held for sale [Member]
Restructuring Cost and Reserve [Line Items]
Assets held for disposal		32,067		32,067
Inventory [Member] | Assets held for sale [Member]
Restructuring Cost and Reserve [Line Items]
Assets held for disposal		9,968		9,968
Property, plant and equipment [Member] | Assets held for sale [Member]
Restructuring Cost and Reserve [Line Items]
Assets held for disposal		$ 22,099		$ 22,099

Related party transactions - Su

Related party transactions - Summary of related party transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Related Party Transaction [Line Items]
Net sales to Glencore	$ 428,018	$ 324,775	$ 1,517,428	$ 898,931
Glencore [Member]
Related Party Transaction [Line Items]
Net sales to Glencore	428,018	324,775	1,517,428	898,931
Purchases from Glencore	86,664	69,256	328,120	194,111
BHH [Member]
Related Party Transaction [Line Items]
Purchases from BHH	$ 13,515	$ 10,715	$ 41,768	$ 38,438

Related party transactions - Na

Related party transactions - Narrative (Details)	Sep. 30, 2015
Glencore [Member]
Related Party Transaction [Line Items]
Ownership percentage by majority shareholder	47.60%
BHH [Member]
Related Party Transaction [Line Items]
Ownership percentage	40.00%

Business acquisitions - Acquisi

Business acquisitions - Acquisition of Mt. Holly smelter narrative other units (Details) - Mt. Holly Smelter [Member] t in Thousands	Dec. 01, 2014employeet	Oct. 23, 2014
Business Acquisition [Line Items]
Remaining percentage acquired in step acquisition		50.30%
Percentage of ownership after step acquisition	100.00%
Employees	600
Mt Holly primary aluminum capacity (tonnes) | t	231

Business acquisitions - Summary

Business acquisitions - Summary of consideration transferred (Details) - USD ($) $ in Thousands	Dec. 01, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition [Line Items]
Purchase price		$ 0	$ 1,042
Mt. Holly Smelter [Member]
Business Acquisition [Line Items]
Purchase price	$ 67,500
Contingent consideration	13,780
Economic, working capital and other closing adjustments	(13,513)
Total consideration transferred	$ 67,767

Business acquisitions - Acqui42

Business acquisitions - Acquisition of Mt. Holly smelter narrative (Details) - USD ($) $ in Thousands	Dec. 01, 2014	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015
Business Acquisition [Line Items]
Unrealized gain on fair value of contingent consideration				$ 1,523	$ 0	$ 18,337	$ 0
Mt. Holly Smelter [Member]
Business Acquisition [Line Items]
Purchase price	$ 67,500
Acquisition costs			$ 1,087	417		417		$ 417
Contingent consideration, high	22,500
Contingent consideration, low	12,500
Contingent consideration at acquisition date	13,780
Unrealized gain on fair value of contingent consideration				$ 1,523		$ 18,337
Consideration receivable, economic adjustment	11,189
Consideration received for working capital adjustments	124
Consideration received for expected future post-employment benefits	$ 2,400
Equity interest percentage, pre step acquisition	49.70%
Remeasurement of existing equity investment	$ 47,700
Gain on remeasurement of equity investment			$ 15,956					$ 14,638
Consideration transferred	$ 67,767
Pension funding total		$ 34,595

Business acquisitions - Acqui43

Business acquisitions - Acquisition of Mt. Holly smelter table (Details) - Mt. Holly Smelter [Member] $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended	10 Months Ended
	Sep. 30, 2014USD ($)$ / shares	Sep. 30, 2014USD ($)$ / shares	Sep. 30, 2015USD ($)	Dec. 01, 2014USD ($)Agreement
Assets Acquired:
Inventories				$ 23,979
Due from Alumax				11,269
Prepaid and other current assets				2,527
Intangible asset				2,580
Pension asset				30,842
Property, plant and equipment – net				142,837
Total assets acquired				214,034
Liabilities Assumed:
Accounts payable, trade				41,471
Accrued and other current liabilities				8,590
Accrued pension benefit costs				34,595
Accrued postretirement benefit costs				2,857
Asset retirement obligations				8,213
Deferred taxes				2,686
Total liabilities assumed				98,412
Goodwill				0
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustments [Abstract]
Inventories			$ (2,126)
Due from Alumax			(9,517)
Property, plant and equipment – net			15,748
Total assets acquired			4,105
Accrued and other current liabilities			255
Accrued pension benefit costs			34,595
Deferred taxes			(2,118)
Total liabilities assumed			32,732
Goodwill			$ (4,804)
Pro forma information
Pro forma revenues	$ 573,230	$ 1,575,842
Pro forma earnings from continuing operations	$ 58,050	$ 53,824
Pro forma earnings (loss) per common share, basic (in dollars per share) | $ / shares	$ 0.60	$ 0.56
Pro forma earnings (loss) per common share, diluted (in dollars per share) | $ / shares	$ 0.60	$ 0.55
Due from Alumax, purchase price credit				11,269
Alumina Supply Agreements				$ 14,880
Number of alumina supply agreements | Agreement				2
Preliminary estimate [Member]
Assets Acquired:
Inventories				$ 26,105
Due from Alumax				20,786
Prepaid and other current assets				2,527
Intangible asset				2,580
Pension asset				30,842
Property, plant and equipment – net				127,089
Total assets acquired				209,929
Liabilities Assumed:
Accounts payable, trade				41,471
Accrued and other current liabilities				8,335
Accrued pension benefit costs				0
Accrued postretirement benefit costs				2,857
Asset retirement obligations				8,213
Deferred taxes				4,804
Total liabilities assumed				65,680
Goodwill				$ 4,804

Fair value measurements (Detail

Fair value measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
ASSETS:
Cash equivalents	$ 119,194	$ 137,712
Trust assets	5,998	8,067
Surety bonds	1,870	1,987
TOTAL	127,062	147,766
Fair Value, Inputs, Level 1 [Member]
ASSETS:
Cash equivalents	119,194	137,712
Trust assets	5,998	8,067
Surety bonds	1,870	1,987
TOTAL	127,062	147,766
Fair Value, Inputs, Level 2 [Member]
ASSETS:
Cash equivalents	0	0
Trust assets	0	0
Surety bonds	0	0
TOTAL	0	0
Fair Value, Inputs, Level 3 [Member]
ASSETS:
Cash equivalents	0	0
Trust assets	0	0
Surety bonds	0	0
TOTAL	$ 0	$ 0

Earnings (loss) per share (Deta

Earnings (loss) per share (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net income (loss)		$ (56,112)	$ 50,405	$ (16,230)	$ 50,645
Amount allocated to common stockholders (in hundredths)		100.00%	91.81%	100.00%	91.79%
Basic EPS:
Net income (loss) allocated to common stockholders		$ (56,112)	$ 46,277	$ (16,230)	$ 46,487
Net income (loss) allocated to common stockholders - (in Shares)		86,907,000	88,827,000	87,524,000	88,777,000
Net income (loss) allocated to common stockholders (in dollars per share)		$ (0.65)	$ 0.52	$ (0.19)	$ 0.52
Effect of Dilutive Securities:
Share-based compensation plans		$ 0	$ 0	$ 0	$ 0
Share-based compensation plans - (in Shares)		0	705,000	0	595,000
Diluted EPS:
Net income (loss) allocated to common stockholders with assumed conversion		$ (56,112)	$ 46,277	$ (16,230)	$ 46,487
Net income (loss) allocated to common stockholders with assumed conversion - (in Shares)		86,907,000	89,532,000	87,524,000	89,372,000
Net income (loss) allocated to common stockholders with assumed conversion (in dollars per share)		$ (0.65)	$ 0.52	$ (0.19)	$ 0.52
Stock options [Member]
Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from calculation of diluted EPS (in shares)	[1]	317,266	338,433	327,599	344,433
Service-based share awards [Member]
Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from calculation of diluted EPS (in shares)	[1]	646,128	0	599,001	0
[1]	In periods when we report a net loss, all share awards are excluded from the calculation of diluted weighted average shares outstanding because of their antidilutive effect on earnings (loss) per share. In periods when we report net income, certain option awards may be excluded from the calculation of diluted EPS if the exercise price of the option award was greater than the average market price of the underlying common stock.

Shareholders' equity (Details)

Shareholders' equity (Details) - USD ($)	3 Months Ended	9 Months Ended		50 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014	Aug. 01, 2011
Class of Stock [Line Items]
Common stock, shares authorized (in shares)	195,000,000	195,000,000		195,000,000	195,000,000
Stock repurchase program, authorized amount	$ 130,000,000	$ 130,000,000		$ 130,000,000		$ 60,000,000
Stock repurchase program, additional authorized amount	$ 70,000,000	$ 70,000,000		$ 70,000,000
Repurchase of common stock (in shares)	0	2,400,000		7,186,521
Repurchase of common stock, aggregate purchase price		$ 36,352,000		$ 86,276,000
Stock repurchase program, remaining authorized repurchase amount	$ 43,724,000	$ 43,724,000		$ 43,724,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of common stock (in shares)	0	2,400,000		7,186,521
Series A Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)		78,141	79,620
Repurchase of common stock (in shares)		0
Conversion of convertible preferred stock (in shares)		(1,146)	(950)
Issuance for stock compensation plans (in shares)		0	0
Shares, Ending balance (in shares)	76,995	76,995	78,670	76,995
Treasury Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)		2,400,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)		4,786,521	4,786,521
Repurchase of common stock (in shares)		2,400,000
Conversion of convertible preferred stock (in shares)		0	0
Issuance for stock compensation plans (in shares)		0	0
Shares, Ending balance (in shares)	7,186,521	7,186,521	4,786,521	7,186,521
Common Stock [Member]
Class of Stock [Line Items]
Repurchase of common stock (in shares)		(2,400,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares, Beginning balance (in shares)		89,064,582	88,710,277
Repurchase of common stock (in shares)		(2,400,000)
Conversion of convertible preferred stock (in shares)		114,524	95,039
Issuance for stock compensation plans (in shares)		152,597	132,554
Shares, Ending balance (in shares)	86,931,703	86,931,703	88,937,870	86,931,703

Income taxes (Details)

Income taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (2,161)	$ 6,444	$ 12,205	$ 7,004

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Inventory, Net [Abstract]
Raw materials	$ 78,066	$ 78,599
Work-in-process	49,597	33,941
Finished goods	18,412	19,969
Operating and other supplies	152,784	150,971
Total inventories	$ 298,859	$ 283,480

Debt (Details)

Debt (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2015	Dec. 31, 2014
Schedule of Debt Instruments [Line Items]
Industrial revenue bonds		$ 7,815	$ 7,815
TOTAL		$ 254,993	$ 254,703
Industrial revenue bonds due 2028 [Member] | Short-term Debt [Member]
Schedule of Debt Instruments [Line Items]
Effective interest rate percentage, maximum	[1]	12.00%	12.00%
Stated interest rate, percentage		0.22%
Industrial revenue bonds	[1]	$ 7,815	$ 7,815
Senior secured notes due June 01, 2021 [Member] | Long-term Debt [Member]
Schedule of Debt Instruments [Line Items]
Maturity date		Jun. 1, 2021	Jun. 1, 2021
Stated interest rate, percentage		7.50%	7.50%
Debt discount		$ 2,822	$ 3,112
Senior secured notes		$ 247,178	$ 246,888
[1]	The IRBs are classified as current liabilities because they are remarketed weekly and could be required to be repaid upon demand if there is a failed remarketing. The IRB interest rate at September 30, 2015 was 0.22%.

Debt - Credit Facility (Details

Debt - Credit Facility (Details) - Long-term Debt [Member]	May. 24, 2013USD ($)	Sep. 30, 2015USD ($)	Nov. 27, 2013USD ($)
U.S. revolving credit facility [Member]
Line of Credit Facility [Line Items]
Credit facility face amount	$ 150,000,000
Credit facility maximum amount		$ 150,000,000
Borrowing availability, net of outstanding letters of credit		50,026,000
Outstanding borrowings		0
Covenant terms, fixed-charge coverage ratio	1.1
Covenant terms, minimum available borrowing capacity	$ 15,000,000
U.S. letter of credit [Member]
Line of Credit Facility [Line Items]
Letter of credit sub-facility amount	$ 110,000,000	110,000,000
Outstanding letters of credit issued		63,005,000
Iceland revolving line of credit [Member]
Line of Credit Facility [Line Items]
Credit facility face amount			$ 50,000,000
Credit facility maximum amount		50,000,000
Borrowing availability, net of outstanding letters of credit		50,000,000
Outstanding borrowings		$ 0

Debt - E.ON Contingent Obligati

Debt - E.ON Contingent Obligation (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)payment	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Debt Instrument [Line Items]
Unrealized gain on E.ON obligation	$ 1,059	$ 1,059
Other liabilities [Member] | E.ON Contingent Obligation - Net [Member]
Debt Instrument [Line Items]
E.ON contingent obligation – principal	(12,902)		$ (12,902)
E.ON contingent obligation – accrued interest	(6,350)		(5,291)
E.ON contingent obligation – derivative asset	19,252		18,193
E.ON contingent obligation	$ 0		$ 0
Long-term Debt [Member] | E.ON Contingent Obligation - Net [Member]
Debt Instrument [Line Items]
Debt payment terms	72 monthly payments
Number of monthly principal and interest payments | payment	72
Unrealized gain on E.ON obligation	$ 1,059	1,059
Interest Expense [Member] | Long-term Debt [Member] | E.ON Contingent Obligation - Net [Member]
Debt Instrument [Line Items]
Interest expense recorded	$ (1,059)	$ (1,059)

Commitments and contingencies (

Commitments and contingencies (Details) $ in Thousands	1 Months Ended	9 Months Ended		12 Months Ended	45 Months Ended
	Mar. 31, 2015USD ($)	Sep. 30, 2015USD ($)LaborUnions	Sep. 30, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2011MW
Environmental Contingencies [Abstract]
Environmental-related accrued liabilities		$ 1,419				$ 1,101
Environmental remediation expense for Hydrocarbon Recovery Plan		1,085
PBCG Settlement [Abstract]
Pension contributions		34,595	$ 0
OR Power Agreement [Abstract]
Power prepayments		$ 1,792
Power currently available under the power purchase agreement (in megawatts) | MW							47.5
Labor Commitments [Abstract]
Percentage of total work force in union		59.00%
Percentage of Grundartangi work force represented by the labor unions (in hundredths)		81.00%
Number of labor unions Grundartangi subsidiary entered into a new labor agreement with | LaborUnions		5
Percentage of Vlissingen work force represented by the labor union (in hundredths)		80.00%
Percentage of U.S. based work force represented by a union (in hundredths)		53.00%
PBGC Agreement [Member]
PBCG Settlement [Abstract]
Pension contributions	$ 1,076			$ 6,700
PBGC Forecast [Member] | PBGC Agreement [Member]
PBCG Settlement [Abstract]
Pension contributions above required minimum, total					$ 17,400
Hawesville [Member]
PBCG Settlement [Abstract]
Power supply arrangement, minimum extension notice		1 year
Sebree [Member]
PBCG Settlement [Abstract]
Power supply arrangement, minimum extension notice		1 year

Forward delivery contracts an53

Forward delivery contracts and financial instruments (Details) - t	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Primary Aluminum Sales Contracts [Member] | Glencore Nordural Metal Agreement [Member]
Supply Commitment [Line Items]
Customer	Glencore
Volume	All primary aluminum produced at Grundartangi, net of tolling and other sales commitments
Term	January 1, 2014 through December 31, 2017
Pricing	Variable, based on LME and European Duty Paid premium
Primary Aluminum Sales Contracts [Member] | Glencore U.S. Aluminum Sales Agreement [Member]
Supply Commitment [Line Items]
Customer	Glencore
Volume	Substantially all of the primary aluminum produced in North America
Term	January 1, 2015 through December 31, 2016
Pricing	Variable, based on LME and Midwest premium and product premiums, as applicable
Long-Term Tolling Conctracts [Member] | Glencore Toll Agreement [Member]
Supply Commitment [Line Items]
Customer	Glencore
Volume	90,000 tonnes per year ("tpy")
Volume (in tonnes)	90,000
Term	Through July 2016
Pricing	Variable, based on LME and European Duty Paid premium
Other Forward Delivery Contracts [Member]
Supply Commitment [Line Items]
Other forward delivery contracts to sell primary aluminum (in tonnes)	6,486	6,108
Glencore [Member] | Other Forward Delivery Contracts [Member]
Supply Commitment [Line Items]
Other forward delivery contracts to sell primary aluminum (in tonnes)	0	4,058

Supplemental cash flow inform54

Supplemental cash flow information (Details) - USD ($) $ in Thousands		1 Months Ended	9 Months Ended
		Apr. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Income Tax Examination [Line Items]
Interest			$ 9,396	$ 9,684
Income/withholding taxes	[1]		13,921	10,079
Accrued capital costs			2,155	663
Stock issued to settle performance unit liabilities, net of withholding taxes, value		$ 1,516
Iceland [Member]
Income Tax Examination [Line Items]
Income/withholding taxes			$ 8,388	$ 5,491
[1]	We paid withholding taxes of $8,388 and $5,491 in Iceland on intercompany dividends during the nine months ended September 30, 2015 and 2014, respectively. Our tax payments in Iceland for withholding taxes, income taxes and any associated refunds are denominated in Icelandic kronur ("ISK").

Asset retirement obligations 55

Asset retirement obligations (“ARO”) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Asset Retirement Obligation [Roll Forward]
Beginning balance, ARO liability	$ 36,950	$ 27,113
Additional ARO liability incurred	3,723	2,548
ARO liabilities settled	(5,206)	(4,731)
Accretion expense	1,360	1,517
Adjustments	(1,886)	0
ARO liability from Mt. Holly acquisition	0	10,503
Ending balance, ARO liability	$ 34,941	$ 36,950

Components of accumulated oth56

Components of accumulated other comprehensive loss (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive loss before income tax effect							$ (112,949)	$ (129,913)
Income tax effect	[1]						11,083	12,231
Accumulated other comprehensive loss		$ (98,242)	$ (91,864)	$ (117,682)		$ (91,832)	(101,866)	(117,682)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning		(98,242)	(91,864)	(117,682)		(91,832)
Other comprehensive income (loss) before reclassifications		(4,114)	(17)	13,928	[2]	389
Net amount reclassified to net income (loss)		490	(136)	1,888		(574)
Accumulated other comprehensive loss, ending		(101,866)	(92,017)	(101,866)		(92,017)
Defined benefit plan and other postretirement liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive loss before income tax effect							(111,560)	(128,664)
Income tax effect							11,639	12,812
Accumulated other comprehensive loss		(96,335)	(77,843)	(115,852)		(77,921)	(99,920)	(115,852)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning		(96,335)	(77,843)	(115,852)		(77,921)
Other comprehensive income (loss) before reclassifications		(4,114)	0	13,928	[2]	440
Net amount reclassified to net income (loss)		529	(98)	2,004		(460)
Accumulated other comprehensive loss, ending		(99,920)	(77,941)	(99,920)		(77,941)
Equity in investee other comprehensive income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss		0	(12,266)	0		(12,232)	0	0
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning		0	(12,266)	0		(12,232)
Other comprehensive income (loss) before reclassifications		0	(17)	0	[2]	(51)
Net amount reclassified to net income (loss)		0	0	0		0
Accumulated other comprehensive loss, ending		0	(12,283)	0		(12,283)
Unrealized loss on financial instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive loss before income tax effect							(1,389)	(1,249)
Income tax effect							(556)	(581)
Accumulated other comprehensive loss		(1,907)	(1,755)	(1,830)		(1,679)	$ (1,946)	$ (1,830)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive loss, beginning		(1,907)	(1,755)	(1,830)		(1,679)
Other comprehensive income (loss) before reclassifications		0	0	0	[2]	0
Net amount reclassified to net income (loss)		(39)	(38)	(116)		(114)
Accumulated other comprehensive loss, ending		$ (1,946)	$ (1,793)	$ (1,946)		$ (1,793)
[1]	The allocation of the income tax effect to the components of other comprehensive income is as follows: Defined benefit plan liabilities of $11,639 and $12,812 and Unrealized losses on financial instruments of (556) and (581) at September 30, 2015 and December 31, 2014, respectively.
[2]	The gain in other comprehensive income before reclassifications is due to a plan remeasurement related to our labor negotiations, census and other actuarial adjustments.

Components of accumulated oth57

Components of accumulated other comprehensive loss - Reclassifications out of AOCI (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	$ 496,963	$ 424,918	$ 1,505,928	$ 1,267,343
Selling, general and administrative expenses	11,566	12,146	33,549	32,826
Income tax expense	(2,161)	6,444	12,205	7,004
Net of tax	(56,112)	50,405	(16,230)	50,645
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined benefit plan and other postretirement liabilities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	669	308	2,422	924
Selling, general and administrative expenses	252	142	755	427
Income tax expense	(392)	(548)	(1,173)	(1,811)
Net of tax	529	(98)	2,004	(460)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized loss on financial instruments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of goods sold	(47)	(46)	(140)	(139)
Income tax expense	8	8	24	25
Net of tax	$ (39)	$ (38)	$ (116)	$ (114)

Components of net periodic be58

Components of net periodic benefit cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 2,074	$ 1,333	$ 5,287	$ 3,999
Interest cost	3,348	2,871	10,003	8,612
Expected return on plan assets	(5,262)	(3,550)	(16,025)	(10,648)
Amortization of prior service costs	28	9	83	27
Amortization of net loss	1,025	477	3,049	1,430
Curtailment	377	0	365	0
Net periodic benefit cost	1,590	1,140	2,762	3,420
Employer contributions			3,551
Other Postretirement Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	468	397	1,517	1,191
Interest cost	1,542	1,603	4,523	4,809
Amortization of prior service costs	(1,007)	(961)	(2,929)	(2,883)
Amortization of net loss	874	925	2,973	2,777
Net periodic benefit cost	$ 1,877	$ 1,964	$ 6,084	$ 5,894

Subsequent events (Details)

Subsequent events (Details) - Sebree, Kentucky [Member] - Subsequent Event [Member]	Oct. 30, 2015potline
Subsequent Event [Line Items]
Curtailment notice, number of intended potline closings	1
Number of potlines	3