Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 105,009	$ 19,363
Investments, at fair market value	149,879	188,988
Inventories	156,285	101,806
Trade receivables	7,773	7,380
Deferred income taxes	29,027	17,890
Other current assets	11,952	13,940
Total current assets	459,925	349,367
Property, plant and equipment, net of $408,497 and $378,390 of accumulated depletion, depreciation and amortization	531,854	509,787
Restricted cash	35,070	38,070
Other noncurrent assets	12,088	12,246
Total assets	1,038,937	909,470
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable	24,049	19,405
Accrued compensation and benefits	29,095	24,746
Property, production and franchise taxes payable	12,815	10,999
Income taxes payable	9,821
Other current liabilities	7,665	3,052
Total current liabilities	83,445	58,202
Long-term debt	196,027	196,010
Deferred income taxes	64,996	53,859
Accrued workers compensation	6,601	7,155
Asset retirement obligation	7,033	6,747
Other noncurrent liabilities	5,553	4,425
Total liabilities	363,655	326,398
Stockholders' equity
Preferred stock, $0.01 par value, 1,000,000 shares authorized; none issued
Common stock, $0.01 par value, 200,000,000 shares authorized; 103,056,185 and 101,881,816 shares issued and outstanding	1,031	1,019
Paid-in capital	774,887	761,475
Accumulated deficit	(99,680)	(178,570)
Accumulated other comprehensive loss	(956)	(852)
Total stockholders' equity	675,282	583,072
Total liabilities and stockholders' equity	$ 1,038,937	$ 909,470