Supplemental Guarantor and Non-Guarantor Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Sales									$ 1,374,422	$ 1,836,343	$ 2,381,760
Miscellaneous income									32,923	24,288	18,135
Total revenues	285,563	329,546	378,351	413,885	471,996	455,796	441,496	491,343	1,407,345	1,860,631	2,399,895
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)									1,266,757	1,558,305	1,796,991
Depreciation and depletion									262,525	311,514	316,232
Selling, general and administrative									72,015	99,994	133,467
Other postretirement benefits									55,476	58,900	52,852
Restructuring and asset impairments									57,508	2,883	49,070
Goodwill impairment									0	0	1,064,409
Total costs and expenses									1,714,281	2,031,596	3,413,021
Operating loss	(105,602)	(54,833)	(99,439)	(47,062)	(17,711)	(59,081)	(30,553)	(63,620)	(306,936)	(170,965)	(1,013,126)
Interest income (expense), net									(295,903)	(221,583)	(132,997)
Gain on extinguishment of debt	32,800	3,400	11,400	(13,900)		(900)		6,000	33,673	(6,875)	(5,555)
Other income (loss), net									646	(1,418)	(13,081)
Loss from continuing operations before income tax benefit									(568,520)	(400,841)	(1,164,759)
Income tax expense (benefit)									(97,952)	(41,838)	(99,204)
Loss from continuing operations	(128,097)	(98,902)	(151,391)	(92,178)	(174,343)	(100,724)	(34,492)	(49,444)	(470,568)	(359,003)	(1,065,555)
Income from discontinued operations									0	0	5,180
Equity in net losses of subsidiaries									0	0	0
Net loss									(470,568)	(359,003)	(1,060,375)
Parent (Issuer)
Revenues:
Sales									0	0	0
Miscellaneous income									1,206	88	2,233
Total revenues									1,206	88	2,233
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)									0	0	0
Depreciation and depletion									2,456	2,150	1,379
Selling, general and administrative									6,276	4,393	11,716
Other postretirement benefits									(177)	(218)	(449)
Restructuring and asset impairments									564	0	0
Goodwill impairment											0
Total costs and expenses									9,119	6,325	12,646
Operating loss									(7,913)	(6,237)	(10,413)
Interest income (expense), net									(299,405)	(252,144)	(151,488)
Gain on extinguishment of debt									33,673	(6,875)	(5,555)
Other income (loss), net									704	(300)	0
Loss from continuing operations before income tax benefit									(272,941)	(265,556)	(167,456)
Income tax expense (benefit)									(184)	(51,821)	(68,615)
Loss from continuing operations											(98,841)
Income from discontinued operations											0
Equity in net losses of subsidiaries									(197,811)	(145,268)	(961,534)
Net loss									(470,568)	(359,003)	(1,060,375)
Guarantor Subsidiaries
Revenues:
Sales									1,136,548	1,304,806	1,702,246
Miscellaneous income									13,631	11,201	21,047
Total revenues									1,150,179	1,316,007	1,723,293
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)									963,015	985,176	1,142,914
Depreciation and depletion									148,218	157,065	165,300
Selling, general and administrative									47,167	53,415	72,962
Other postretirement benefits									55,653	59,118	53,301
Restructuring and asset impairments									52,223	(7,763)	0
Goodwill impairment											74,319
Total costs and expenses									1,266,276	1,247,011	1,508,796
Operating loss									(116,097)	68,996	214,497
Interest income (expense), net									6,458	27,877	22,909
Gain on extinguishment of debt									0	0	0
Other income (loss), net									(2)	(1,336)	0
Loss from continuing operations before income tax benefit									(109,641)	95,537	237,406
Income tax expense (benefit)									0	111,527	73,379
Loss from continuing operations											164,027
Income from discontinued operations											5,180
Equity in net losses of subsidiaries									0	0	0
Net loss									(109,641)	(15,990)	169,207
Non-Guarantor Subsidiaries
Revenues:
Sales									237,874	531,537	679,514
Miscellaneous income									18,086	12,999	(5,145)
Total revenues									255,960	544,536	674,369
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)									303,742	573,129	654,077
Depreciation and depletion									111,851	152,299	149,553
Selling, general and administrative									18,572	42,186	48,789
Other postretirement benefits									0	0	0
Restructuring and asset impairments									4,721	10,646	49,070
Goodwill impairment											990,090
Total costs and expenses									438,886	778,260	1,891,579
Operating loss									(182,926)	(233,724)	(1,217,210)
Interest income (expense), net									(2,956)	2,684	(4,418)
Gain on extinguishment of debt									0	0	0
Other income (loss), net									(56)	218	(13,081)
Loss from continuing operations before income tax benefit									(185,938)	(230,822)	(1,234,709)
Income tax expense (benefit)									(97,768)	(101,544)	(103,968)
Loss from continuing operations											(1,130,741)
Income from discontinued operations											0
Equity in net losses of subsidiaries									0	0	0
Net loss									(88,170)	(129,278)	(1,130,741)
Eliminations
Revenues:
Sales									0	0	0
Miscellaneous income									0	0	0
Total revenues									0	0	0
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)									0	0	0
Depreciation and depletion									0	0	0
Selling, general and administrative									0	0	0
Other postretirement benefits									0	0	0
Restructuring and asset impairments									0	0	0
Goodwill impairment											0
Total costs and expenses									0	0	0
Operating loss									0	0	0
Interest income (expense), net									0	0	0
Gain on extinguishment of debt									0	0	0
Other income (loss), net									0	0	0
Loss from continuing operations before income tax benefit									0	0	0
Income tax expense (benefit)									0	0
Loss from continuing operations											0
Income from discontinued operations											0
Equity in net losses of subsidiaries									197,811	145,268	961,534
Net loss									$ 197,811	$ 145,268	$ 961,534