Supplemental Guarantor and Non-Guarantor Financial Information (Income Statement) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenues:
Sales	$ 285,646	$ 405,229
Miscellaneous income	5,280	8,656
Total revenues	290,926	413,885
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	284,693	349,875
Depreciation and depletion	59,182	76,424
Selling, general and administrative	21,061	20,779
Other postretirement benefits	12,333	13,869
Total costs and expenses	377,269	460,947
Operating loss	(86,343)	(47,062)
Interest expense, net	(78,236)	(65,432)
Gain (loss) on extinguishment of debt	58,626	(13,889)
Other loss	0	(1,756)
Loss before income tax benefit	(105,953)	(128,139)
Income tax expense (benefit)	(25,757)	(35,961)
Equity in net losses of subsidiaries	0	0
Net loss	(80,196)	(92,178)
Reportable legal entities | Parent (Issuer)
Revenues:
Sales	0	0
Miscellaneous income	453	655
Total revenues	453	655
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	0	0
Depreciation and depletion	575	648
Selling, general and administrative	5,383	1,153
Other postretirement benefits	(67)	(44)
Total costs and expenses	5,891	1,757
Operating loss	(5,438)	(1,102)
Interest expense, net	(76,356)	(72,404)
Gain (loss) on extinguishment of debt	58,626	(13,889)
Other loss		(1,700)
Loss before income tax benefit	(23,168)	(89,095)
Income tax expense (benefit)	0	(18,561)
Equity in net losses of subsidiaries	(57,028)	(21,644)
Net loss	(80,196)	(92,178)
Reportable legal entities | Guarantor Subsidiaries
Revenues:
Sales	248,370	324,911
Miscellaneous income	255	1,879
Total revenues	248,625	326,790
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	232,416	254,041
Depreciation and depletion	36,264	38,101
Selling, general and administrative	12,495	13,858
Other postretirement benefits	12,400	13,913
Total costs and expenses	293,575	319,913
Operating loss	(44,950)	6,877
Interest expense, net	(195)	7,234
Gain (loss) on extinguishment of debt	0	0
Other loss		0
Loss before income tax benefit	(45,145)	14,111
Income tax expense (benefit)	0	2,629
Equity in net losses of subsidiaries	0	0
Net loss	(45,145)	11,482
Reportable legal entities | Non-Guarantor Subsidiaries
Revenues:
Sales	37,276	80,318
Miscellaneous income	4,572	6,122
Total revenues	41,848	86,440
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	52,277	95,834
Depreciation and depletion	22,343	37,675
Selling, general and administrative	3,183	5,768
Other postretirement benefits	0	0
Total costs and expenses	77,803	139,277
Operating loss	(35,955)	(52,837)
Interest expense, net	(1,685)	(262)
Gain (loss) on extinguishment of debt	0	0
Other loss		(56)
Loss before income tax benefit	(37,640)	(53,155)
Income tax expense (benefit)	(25,757)	(20,029)
Equity in net losses of subsidiaries	0	0
Net loss	(11,883)	(33,126)
Eliminations
Revenues:
Sales	0	0
Miscellaneous income	0	0
Total revenues	0	0
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	0	0
Depreciation and depletion	0	0
Selling, general and administrative	0	0
Other postretirement benefits	0	0
Total costs and expenses	0	0
Operating loss	0	0
Interest expense, net	0	0
Gain (loss) on extinguishment of debt	0	0
Other loss		0
Loss before income tax benefit	0	0
Income tax expense (benefit)	0	0
Equity in net losses of subsidiaries	57,028	21,644
Net loss	$ 57,028	$ 21,644