Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Current Assets:
Cash and cash equivalents	$ 97		$ 170
Accounts receivable	68,814		67,318
Deferred tax asset	4,324		5,679
Other current assets	7,623		7,370
Total Current Assets	80,858		80,537
Property and Equipment:
Property and Equipment	5,607,100		5,192,793
Less - Accumulated depreciation, depletion, and amortization	(3,034,614)		(2,847,773)
Property and Equipment, Net	2,572,486		2,345,020
Other Long-Term Assets	17,411		18,504
Total Assets	2,670,755		2,444,061
Current Liabilities:
Accounts payable and accrued liabilities	81,608		75,378
Accrued capital costs	58,058		73,190
Accrued interest	13,105		21,362
Undistributed oil and gas revenues	7,996		7,550
Total Current Liabilities	160,767		177,480
Long-Term Debt	1,120,402	[1]	916,934	[1]
Deferred Tax Liabilities	238,622		223,243
Asset Retirement Obligation	68,628		79,643
Other Long-Term Liabilities	10,253		9,901
Commitments and Contingencies	0		0
Stockholders' Equity:
Preferred stock, $0.01 par value	0		0
Common stock, $0.01 par value	439		435
Additional paid-in capital	758,971		747,868
Treasury stock held, at cost	(12,556)		(13,855)
Retained earnings	325,229		302,412
Total Stockholders' Equity	1,072,083		1,036,860
Total Liabilities and Stockholders' Equity	$ 2,670,755		$ 2,444,061

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