Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Current Assets:
Cash and cash equivalents	$ 170		$ 251,696
Accounts receivable	67,318		68,360
Deferred tax asset	5,679		6,603
Other current assets	7,370		5,460
Total Current Assets	80,537		332,119
Property and Equipment:
Property and Equipment, including $92,579 and $84,146 of unproved property costs not being amortized, respectively	5,192,793		4,466,845
Less - Accumulated depreciation, depletion, and amortization	(2,847,773)		(2,599,079)
Property and Equipment, Net	2,345,020		1,867,766
Other Long-Term Assets	18,504		16,552
Total Assets	2,444,061		2,216,437
Current Liabilities:
Accounts payable and accrued liabilities	75,378		95,966
Accrued capital costs	73,190		98,844
Accrued interest	21,362		12,459
Undistributed oil and gas revenues	7,550		8,493
Total Current Liabilities	177,480		215,762
Long-Term Debt	916,934	[1]	719,775	[1]
Deferred Tax Liabilities	223,243		206,567
Asset Retirement Obligation	79,643		67,115
Other Long-Term Liabilities	9,901		10,709
Commitments and Contingencies	0		0
Stockholders' Equity:
Preferred stock, $.01 par value, 5,000,000 shares authorized, none outstanding	0		0
Common stock, $.01 par value, 150,000,000 shares authorized, 43,450,367 and 42,969,546 shares issued, and 42,930,071 and 42,485,075 shares outstanding, respectively	435		430
Additional paid-in capital	747,868		726,956
Treasury stock held, at cost, 520,296 and 484,471 shares, respectively	(13,855)		(12,350)
Retained earnings	302,412		281,473
Accumulated other comprehensive loss, net of income tax	0		0
Total Stockholders' Equity	1,036,860		996,509
Total Liabilities and Stockholders' Equity	$ 2,444,061		$ 2,216,437

[1] Amounts are shown net of any debt discount