Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Net loss	$ (124,139)	$ (70,049)
Derivative instruments
Comprehensive loss before tax	(229)	(1,179)
Income tax benefit	82	425
Derivatives Qualifying as Hedges, Adjustment, Net of Tax	(147)	(754)
Pension, postretirement and other post-employment benefits
Comprehensive income (loss) before tax	(1,847)	1,954
Income tax benefit (provision)	665	(703)
Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(1,182)	1,251
Available-for-sale securities
Comprehensive income (loss) before tax	(2,033)	1,553
Income tax benefit (provision)	732	(559)
Available-for-sale Securities Adjustment, Net of Tax	(1,301)	994
Total other comprehensive income (loss)	(2,630)	1,491
Total comprehensive loss	$ (126,769)	$ (68,558)