Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income (loss)	$ (558,353)us-gaap_ProfitLoss	$ (641,832)us-gaap_ProfitLoss	$ (683,687)us-gaap_ProfitLoss
Derivative instruments
Comprehensive income (loss) before tax	3,102	(2,626)	10,894
Income tax benefit (provision)	(1,117)	947	(3,921)
Derivatives Qualifying as Hedges, Adjustment, Net of Tax	1,985	(1,679)	6,973
Pension, postretirement and other post-employment benefits
Comprehensive income (loss) before tax	(44,143)	77,201	(21,291)
Income tax benefit (provision)	(15,891)	27,803	(7,686)
Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(28,252)	49,398	(13,605)
Available-for-sale securities
Comprehensive income (loss) before tax	(12,788)	10,190	(3,000)
Income tax benefit (provision)	4,604	(3,710)	1,080
Available-for-sale Securities Adjustment, Net of Tax	(8,184)	6,480	(1,920)
Total other comprehensive income (loss)	(34,451)	54,199	(8,552)
Total comprehensive income (loss)	$ (592,804)	$ (587,633)	$ (692,239)

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income. Excludes changes in equity resulting from investments by owners and distributions to owners.

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