Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Current Assets:
Cash and cash equivalents	$ 91		$ 3,277
Accounts receivable	73,581		70,897
Deferred tax asset	10,852		10,715
Other current assets	9,726		7,600
Total Current Assets	94,250		92,489
Property and Equipment:
Property and Equipment	5,813,305		5,714,099
Less - Accumulated depreciation, depletion, and amortization	(3,188,238)		(3,125,282)
Property and Equipment, Net	2,625,067		2,588,817
Other Long-Term Assets	15,585		17,199
Total Assets	2,734,902		2,698,505
Current Liabilities:
Accounts payable and accrued liabilities	79,542		82,318
Accrued capital costs	56,533		61,164
Accrued interest	13,140		21,561
Undistributed oil and gas revenues	13,170		10,990
Total Current Liabilities	162,385		176,033
Long-Term Debt	1,175,036	[1]	1,142,368	[1]
Deferred Tax Liabilities	247,606		241,205
Asset Retirement Obligation	64,503		63,225
Other Long-Term Liabilities	9,831		10,324
Commitments and Contingencies	0		0
Stockholders' Equity:
Preferred stock, $0.01 par value	0		0
Common stock, $0.01 par value	442		439
Additional paid-in capital	764,058		762,242
Treasury stock held, at cost	(9,645)		(12,575)
Retained earnings	320,686		315,244
Total Stockholders' Equity	1,075,541		1,065,350
Total Liabilities and Stockholders' Equity	$ 2,734,902		$ 2,698,505

[1] Amounts are shown net of any debt discount or premium