CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 17,650	$ 7,512
Accounts receivable, net of allowance for doubtful accounts	62,978	72,432
Derivative assets	11,292	18,987
Income taxes receivable	0	31,465
Other current assets	4,595	14,950
Total current assets	96,515	145,346
Property and equipment, net (successful efforts method)	1,723,359	1,777,575
Derivative assets	5,181	0
Other assets	17,934	20,132
Total assets	1,842,989	1,943,053
Current liabilities
Accounts payable and accrued liabilities	111,655	94,504
Derivative liabilities	0	3,549
Deferred income taxes	370	3,808
Current portion of long-term debt	0	4,746
Total current liabilities	112,025	106,607
Other liabilities	28,901	15,887
Derivative liabilities	1,421	6,850
Deferred income taxes	210,767	274,839
Long-term debt	594,759	692,561
Commitments and contingencies (Note 12)
Shareholders’ equity:
Preferred stock of $100 par value – 100,000 shares authorized; shares issued of 11,500 as of December 31, 2012 and none as of December 31, 2011	1,150	0
Common stock of $0.01 par value – 128,000,000 shares authorized; shares issued of 55,117,346 and 45,714,191 as of December 31, 2012 and December 31, 2011, respectively	364	270
Paid-in capital	849,046	690,131
Retained earnings	45,790	157,242
Deferred compensation obligation	3,111	3,620
Accumulated other comprehensive loss	(982)	(1,084)
Treasury stock – 218,320 and 223,886 shares of common stock, at cost, as of December 31, 2012 and December 31, 2011, respectively	(3,363)	(3,870)
Total shareholders’ equity	895,116	846,309
Total liabilities and shareholders’ equity	$ 1,842,989	$ 1,943,053