Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 31,671		$ 251,696
Accounts receivable	51,878		64,392
Deferred tax asset	4,203		6,603
Other current assets	10,041		5,460
Total Current Assets	97,793		328,151
Property and Equipment:
Property and Equipment	4,845,484		4,466,845
Less - Accumulated depreciation, depletion, and amortization	(2,722,546)		(2,599,079)
Property and Equipment, Net	2,122,938		1,867,766
Other Long-Term Assets	15,290		16,552
Total Assets	2,236,021		2,212,469
Current Liabilities:
Accounts payable and accrued liabilities	89,403		95,966
Accrued capital costs	102,268		98,844
Accrued interest	17,322		12,459
Undistributed oil and gas revenues	3,264		4,525
Total Current Liabilities	212,257		211,794
Long-Term Debt	719,977	[1]	719,775	[1]
Deferred Tax Liabilities	208,440		206,567
Asset Retirement Obligation	70,972		67,115
Other Long-Term Liabilities	10,688		10,709
Commitments and Contingencies	0		0
Stockholders' Equity:
Preferred stock, $0.01 par value, 5,000,000 shares authorized, none outstanding	0		0
Common stock, $0.01 par value, 150,000,000 shares authorized, 43,398,351 and 42,969,546 shares issues, and 42,884,215 and 42,485,075 shares outstanding, respectively	434		430
Additional paid-in capital	738,918		726,956
Treasury stock held, at cost, 514,136 and 484,471 shares, respectively	(13,736)		(12,350)
Retained earnings	288,071		281,473
Accumulated other comprehensive income, net of income tax	0		0
Total Stockholders' Equity	1,013,687		996,509
Total Liabilities and Stockholders' Equity	$ 2,236,021		$ 2,212,469

[1] Amounts are shown net of debt discount