Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 7,319	$ 80,128
Trade accounts receivable - net	29,273	31,817
Fair value of commodity derivative instruments	2,792	587
Prepaid expenses	6,984	11,046
Total current assets	46,368	123,578
Property and equipment, at cost under the successful efforts method of accounting	1,264,820	1,082,248
Less accumulated depreciation, depletion, amortization and impairments	(390,545)	(305,110)
Net property and equipment	874,275	777,138
Deposit for Hilcorp Acquisition	55,000
Restricted cash	6,023	6,023
Other assets	3,059	3,029
Fair value of commodity derivative instruments	699
Deferred financing costs -- net of accumulated amortization of $2,032 at September 30, 2012 and $1,061 at December 31, 2011	4,487	5,452
Total Assets	989,911	915,220
Current liabilities:
Accounts payable	31,891	25,393
Accrued expenses	73,425	58,538
Asset retirement obligations	24,496	25,578
Fair value of commodity derivative instruments	9,779	1,056
Deferred tax liabilities	332	2,823
Total current liabilities	139,923	113,388
Long-term debt	204,935	204,390
Asset retirement obligations	70,644	73,769
Deferred tax liabilities	50,274	31,775
Fair value of commodity derivative instruments	2,423	190
Other	1,156	663
Total Liabilities	469,355	424,175
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value. Authorized 1,000,000 shares; no shares issued and outstanding at September 30, 2012 and December 31, 2011
Common stock, par value $0.001 per share. Authorized 75,000,000 shares; shares issued: 40,580,342 and 40,326,451 at September 30, 2012 and December 31, 2011, respectively; shares outstanding: 39,089,591 and 39,404,106 at September 30, 2012 and December 31, 2011, respectively	40	40
Additional paid-in capital	509,041	505,235
Treasury stock, at cost, 1,490,751 and 922,345 shares at September 30, 2012 and December 31, 2011, respectively	(20,313)	(11,361)
Retained earnings (accumulated deficit)	31,788	(2,869)
Total stockholders' equity	520,556	491,045
Total liabilities and stockholders' equity	$ 989,911	$ 915,220