Consolidated Statement of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues [Abstract]
Natural gas sales	$ 228,573	$ 234,785	$ 500,111	$ 436,985
Oil sales	67,490	26,591	122,250	50,018
Oil and Gas Revenue	296,063	261,376	622,361	487,003
Operating Expenses [Abstract]
Lease operating expenses	22,959	17,514	43,972	36,331
LGS operating lease expense	5,076	5,000	10,153	10,000
Production taxes	24,594	20,006	50,525	36,561
Gathering fees	13,449	13,834	26,157	25,718
Transportation charges	17,273	20,649	37,848	40,958
Depletion, depreciation and amoritzation	65,341	60,123	128,522	121,591
General and administrative	2,158	5,876	8,503	11,837
Costs and Expenses	150,850	143,002	305,680	282,996
Operating Income (Loss)	145,213	118,374	316,681	204,007
Other Nonoperating Income (Expense) [Abstract]
Interest Expense, Debt	(27,294)	(25,238)	(54,362)	(51,002)
Gain (loss) on commodity derivatives	(15,102)	22,091	(60,375)	(22,624)
Deferred gain on sale of liquids gathering system	2,638	2,636	5,276	5,276
Other income (expense) net	50	5	2	13
Other Nonoperating Income (Expense)	(39,708)	(506)	(109,459)	(68,337)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest	105,505	117,868	207,222	135,670
Income Tax Expense (Benefit)	(544)	1,491	(541)	2,859
Net Income (Loss)	$ 106,049	$ 116,377	$ 207,763	$ 132,811
Earnings Per Share, Basic [Abstract]
Earnings Per Share, Basic	$ 0.69	$ 0.76	$ 1.36	$ 0.87
Fully Diluted Earnings per Share:
Earnings Per Share, Diluted	$ 0.68	$ 0.75	$ 1.34	$ 0.86
Weighted Average Number of Shares Outstanding, Basic	153,179	152,948	153,110	152,947
Weighted Average Number of Shares Outstanding, Diluted	155,007	154,513	154,915	154,397