Supplemental Guarantor and Non-Guarantor Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Revenues:
Sales	$ 405,229	$ 489,609
Miscellaneous income	8,656	1,734
Total revenues	413,885	491,343
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)	349,875	420,934
Depreciation and depletion	76,424	81,190
Selling, general and administrative	20,779	30,674
Postretirement benefits	13,869	14,725
Restructuring charges		7,440
Total costs and expenses	460,947	554,963
Operating loss	(47,062)	(63,620)
Interest expense	(79,396)	(52,618)
Interest income	75	650
Other loss	(1,756)	105
Loss before income tax benefit	(128,139)	(115,483)
Income tax expense (benefit)	(35,961)	(66,039)
Net loss	(92,178)	(49,444)
Reportable legal entities | Parent (Issuer)
Revenues:
Miscellaneous income	655	553
Total revenues	655	553
Cost and expenses:
Depreciation and depletion	648	485
Selling, general and administrative	1,153	6,211
Postretirement benefits	(44)	(55)
Total costs and expenses	1,757	6,641
Operating loss	(1,102)	(6,088)
Interest expense	(86,307)	(59,167)
Interest income	14	1,670
Other loss	(1,700)
Loss before income tax benefit	(89,095)	(63,585)
Income tax expense (benefit)	(18,561)	(26,667)
Equity in net losses of subsidiaries	(21,644)	(12,526)
Net loss	(92,178)	(49,444)
Reportable legal entities | Guarantor Subsidiaries
Revenues:
Sales	306,042	314,812
Miscellaneous income	1,872	2,190
Total revenues	307,914	317,002
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)	235,366	247,677
Depreciation and depletion	35,208	40,410
Selling, general and administrative	12,936	13,333
Postretirement benefits	13,913	14,780
Restructuring charges		116
Total costs and expenses	297,423	316,316
Operating loss	10,491	686
Interest income	7,254	6,980
Loss before income tax benefit	17,745	7,666
Income tax expense (benefit)	3,394	(3,396)
Net loss	14,351	11,062
Reportable legal entities | Non-Guarantor Subsidiaries
Revenues:
Sales	99,187	174,797
Miscellaneous income	6,129	(1,009)
Total revenues	105,316	173,788
Cost and expenses:
Cost of sales (exclusive of depreciation and depletion)	114,509	173,257
Depreciation and depletion	40,568	40,295
Selling, general and administrative	6,690	11,130
Restructuring charges		7,324
Total costs and expenses	161,767	232,006
Operating loss	(56,451)	(58,218)
Interest expense	(343)	(3,052)
Interest income	61	1,601
Other loss	(56)	105
Loss before income tax benefit	(56,789)	(59,564)
Income tax expense (benefit)	(20,794)	(35,976)
Net loss	(35,995)	(23,588)
Eliminations
Cost and expenses:
Interest expense	7,254	9,601
Interest income	(7,254)	(9,601)
Equity in net losses of subsidiaries	21,644	12,526
Net loss	$ 21,644	$ 12,526