CONDENSED CONSOLIDATED BALANCE SHEETS (Cloud Peak Energy Inc. and Subsidiaries) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets
Cash and cash equivalents	$ 437,560	$ 340,101
Restricted cash	74,321	182,072
Accounts receivable, net	97,462	65,173
Due from related parties	1,382	434
Inventories	72,691	64,970
Deferred income taxes	22,794	21,552
Other assets	21,976	17,449
Total current assets	728,186	691,751
Non-current assets
Property, plant and equipment, net	1,322,097	1,008,337
Goodwill	35,634	35,634
Deferred income taxes	142,592	140,985
Other assets	34,493	38,400
Total assets	2,263,002	1,915,107
Current liabilities
Accounts payable	71,928	81,975
Royalties and production taxes	144,354	127,038
Accrued expenses	56,670	51,197
Current portion of tax agreement liability	9,409	18,226
Current portion of federal coal lease obligations	105,926	54,630
Other liabilities	4,847	4,880
Total current liabilities	393,134	337,946
Non-current liabilities
Tax agreement liability, net of current portion	170,636	171,885
Senior notes	595,977	595,684
Federal coal lease obligations, net of current portion	186,119	63,659
Asset retirement obligations, net of current portion	171,184	182,170
Other liabilities	37,288	32,564
Total liabilities	1,554,338	1,383,908
Commitments and Contingencies (Note 9)
Equity
Common stock ($0.01 par value; 200,000 shares authorized; 60,930 and 60,878 shares issued and outstanding at September 30, 2011 and December 31, 2010, respectively	609	609
Additional paid-in capital	533,813	502,952
Retained earnings	188,274	42,296
Accumulated other comprehensive loss	(14,032)	(14,658)
Total equity	708,664	531,199
Total liabilities and equity	$ 2,263,002	$ 1,915,107