CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 5,033	$ 7,512
Accounts receivable, net of allowance for doubtful accounts	70,039	72,432
Derivative assets	11,252	18,987
Income taxes receivable	0	31,465
Other current assets	5,583	14,950
Total current assets	91,907	145,346
Property and equipment, net (successful efforts method)	1,745,091	1,777,575
Derivative assets	6,892	0
Other assets	18,847	20,132
Total assets	1,862,737	1,943,053
Current liabilities
Accounts payable and accrued liabilities	112,021	94,504
Derivative liabilities	817	3,549
Deferred income taxes	3,807	3,808
Accrued Income Taxes, Current	22	0
Current portion of long-term debt	4,884	4,746
Total current liabilities	121,551	106,607
Other liabilities	29,258	15,887
Derivative liabilities	1,677	6,850
Deferred income taxes	243,522	274,839
Long-term debt	671,447	692,561
Shareholders' equity:
Preferred stock of $100 par value - 100,000 shares authorized; none issued	0	0
Common stock of $0.01 par value - 128,000,000 shares authorized; shares issued of 45,893,146 and 45,714,191 as of September 30, 2012 and December 31, 2011, respectively	271	270
Paid-in capital	694,359	690,131
Retained earnings	101,918	157,242
Deferred compensation obligation	3,072	3,620
Accumulated other comprehensive loss	(1,015)	(1,084)
Treasury stock - 209,392 and 223,886 shares of common stock, at cost, as of September 30, 2012 and December 31, 2011, respectively	(3,323)	(3,870)
Total shareholders' equity	795,282	846,309
Total liabilities and shareholders' equity	$ 1,862,737	$ 1,943,053