Supplemental Guarantor and Non-Guarantor Financial Information (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Supplemental guarantor and non-guarantor financial information
Net income (loss)	$ (359,003,000)	$ (1,060,375,000)	$ 363,598,000
Other comprehensive income (loss), net of tax:
Change in pension and other postretirement benefit plans, net of tax	100,892,000	(40,501,000)	(53,224,000)
Change in unrealized loss on hedges, net of tax	2,524,000	(3,416,000)	(716,000)
Change in foreign currency translation adjustment	6,073,000	1,774,000	(3,276,000)
Change in unrealized gain on investments	(897,000)	769,000	128,000
Total other comprehensive income (loss), net of tax	108,592,000	(41,374,000)	(57,088,000)
Total comprehensive income (loss)	(250,411,000)	(1,101,749,000)	306,510,000
Parent (Issuer)
Supplemental guarantor and non-guarantor financial information
Net income (loss)	(359,003,000)	(1,060,375,000)	363,598,000
Other comprehensive income (loss), net of tax:
Change in pension and other postretirement benefit plans, net of tax	100,892,000	(40,501,000)	(53,224,000)
Change in unrealized loss on hedges, net of tax	2,524,000	(3,416,000)	(716,000)
Change in foreign currency translation adjustment	6,073,000	1,774,000	(3,276,000)
Change in unrealized gain on investments	(897,000)	769,000	128,000
Total other comprehensive income (loss), net of tax	108,592,000	(41,374,000)	(57,088,000)
Total comprehensive income (loss)	(250,411,000)	(1,101,749,000)	306,510,000
Guarantor Subsidiaries
Supplemental guarantor and non-guarantor financial information
Net income (loss)	2,799,000	252,002,000	369,387,000
Other comprehensive income (loss), net of tax:
Change in pension and other postretirement benefit plans, net of tax	91,501,000	(90,876,000)	(9,437,000)
Change in unrealized loss on hedges, net of tax	58,000	95,000	85,000
Total other comprehensive income (loss), net of tax	91,559,000	(90,781,000)	(9,352,000)
Total comprehensive income (loss)	94,358,000	161,221,000	360,035,000
Non-Guarantor Subsidiaries
Supplemental guarantor and non-guarantor financial information
Net income (loss)	(148,067,000)	(1,213,536,000)	70,034,000
Other comprehensive income (loss), net of tax:
Change in unrealized loss on hedges, net of tax		(2,533,000)	2,309,000
Change in foreign currency translation adjustment	6,073,000	1,774,000	(3,276,000)
Change in unrealized gain on investments	(897,000)	769,000	128,000
Total other comprehensive income (loss), net of tax	5,176,000	10,000	(839,000)
Total comprehensive income (loss)	(142,891,000)	(1,213,526,000)	69,195,000
Eliminations
Supplemental guarantor and non-guarantor financial information
Net income (loss)	145,268,000	961,534,000	(439,421,000)
Other comprehensive income (loss), net of tax:
Change in pension and other postretirement benefit plans, net of tax	(91,501,000)	90,876,000	9,437,000
Change in unrealized loss on hedges, net of tax	(58,000)	2,438,000	(2,394,000)
Change in foreign currency translation adjustment	(6,073,000)	(1,774,000)	3,276,000
Change in unrealized gain on investments	897,000	(769,000)	(128,000)
Total other comprehensive income (loss), net of tax	(96,735,000)	90,771,000	10,191,000
Total comprehensive income (loss)	$ 48,533,000	$ 1,052,305,000	$ (429,230,000)