CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues:
Sales	$ 437,798	$ 668,605	$ 927,407	$ 1,295,903
Miscellaneous income	3,698	8,969	5,432	13,234
Total revenues	441,496	677,574	932,839	1,309,137
Costs and expenses:
Cost of sales (exclusive of depreciation and depletion)	367,616	486,084	788,550	917,618
Depreciation and depletion	68,320	74,459	149,510	140,952
Selling, general and administrative	27,129	35,845	57,803	72,092
Postretirement benefits	14,725	13,213	29,450	26,426
Restructuring and asset impairment	(5,741)		1,699
Total costs and expenses	472,049	609,601	1,027,012	1,157,088
Operating income (loss)	(30,553)	67,973	(94,173)	152,049
Interest expense	(53,129)	(31,104)	(105,747)	(59,171)
Interest income	144	341	794	618
Other loss, net	(714)	(5,919)	(609)	(12,912)
Income (loss) from continuing operations before income tax expense (benefit)	(84,252)	31,291	(199,735)	80,584
Income tax expense (benefit)	(49,760)	4,535	(115,799)	13,212
Income (loss) from continuing operations	(34,492)	26,756	(83,936)	67,372
Income from discontinued operations		5,180		5,180
Net income (loss)	$ (34,492)	$ 31,936	$ (83,936)	$ 72,552
Basic income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ (0.55)	$ 0.43	$ (1.34)	$ 1.08
Income from discontinued operations (in dollars per share)		$ 0.08		$ 0.08
Net income (loss) (in dollars per share)	$ (0.55)	$ 0.51	$ (1.34)	$ 1.16
Diluted income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ (0.55)	$ 0.43	$ (1.34)	$ 1.08
Income from discontinued operations (in dollars per share)		$ 0.08		$ 0.08
Net income (loss) (in dollars per share)	$ (0.55)	$ 0.51	$ (1.34)	$ 1.16
Dividends per share (in dollars per share)	$ 0.125	$ 0.125	$ 0.25	$ 0.25