CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
ASSETS
Cash and cash equivalents	$ 129,922	$ 128,430
Receivables, net	229,725	313,343
Inventories	374,239	240,437
Deferred income taxes	43,468	61,079
Prepaid expenses	67,066	49,974
Other current assets	22,096	45,649
Total current assets	866,516	838,912
Mineral interests, net of accumulated depletion of $162.1 million and $84.2 million, respectively	2,980,924	3,056,258
Property, plant and equipment, net of accumulated depreciation of $728.2 million and $614.6 million, respectively	1,720,137	1,631,333
Deferred income taxes	144,604	109,300
Goodwill		1,066,754
Other long-term assets	135,720	153,951
Total assets	5,847,901	6,856,508
LIABILITIES AND STOCKHOLDERS' EQUITY
Current debt	69,327	56,695
Accounts payable	163,653	112,661
Accrued expenses	239,934	229,067
Accumulated postretirement benefits obligation	28,648	27,247
Other current liabilities	42,188	63,757
Total current liabilities	543,750	489,427
Long-term debt	2,278,214	2,269,020
Deferred income taxes	951,835	1,029,336
Accumulated postretirement benefits obligation	559,438	550,671
Other long-term liabilities	374,463	381,537
Total liabilities	4,707,700	4,719,991
Commitments and contingencies (Note 11)
Stockholders' equity:
Common stock, $0.01 par value per share: Authorized-200,000,000 shares, Issued-62,516,687 and 62,444,905 shares, respectively	625	624
Capital in excess of par value	1,626,730	1,620,430
Retained earnings (accumulated deficit)	(268,664)	744,939
Accumulated other comprehensive income (loss):
Pension and other postretirement benefit plans, net of tax	(213,848)	(225,541)
Foreign currency translation adjustment	(934)	(3,276)
Unrealized loss on hedges, net of tax	(4,602)	(787)
Unrealized investment gain (loss), net of tax	894	128
Total stockholders' equity	1,140,201	2,136,517
Total liabilities and stockholders' equity	$ 5,847,901	$ 6,856,508