CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
OPERATING REVENUES
Natural gas	$ 341,901	$ 231,896	$ 1,004,085	$ 639,729
Crude oil and condensate	84,209	57,870	220,090	165,317
Brokered natural gas	7,165	5,238	26,302	23,831
Other	2,575	1,870	8,338	5,790
TOTAL OPERATING REVENUES	435,850	296,874	1,258,815	834,667
OPERATING EXPENSES
Direct operations	32,923	28,269	101,398	84,895
Transportation and gathering	60,803	34,430	159,672	97,827
Brokered natural gas cost	5,913	4,258	21,006	20,380
Taxes other than income	11,532	10,436	34,583	39,873
Exploration	3,891	9,303	12,444	29,548
Depreciation, depletion and amortization	168,980	110,448	469,022	335,421
General and administrative	24,697	23,829	82,009	93,249
TOTAL OPERATING EXPENSES	308,739	220,973	880,134	701,193
Gain / (loss) on sale of assets	4,421	(126)	4,601	67,042
INCOME FROM OPERATIONS	131,532	75,775	383,282	200,516
Interest expense and other	15,796	16,219	48,752	51,631
Income before income taxes	115,736	59,556	334,530	148,885
Income tax expense	45,847	22,948	132,703	58,021
NET INCOME	$ 69,889	$ 36,608	$ 201,827	$ 90,864
Earnings per share
Basic (in dollars per share)	$ 0.17	$ 0.09	$ 0.48	$ 0.22
Diluted (in dollars per share)	$ 0.17	$ 0.09	$ 0.48	$ 0.22
Weighted-average shares outstanding
Basic (in shares)	420,986	419,312	420,664	418,866
Diluted (in shares)	423,453	422,452	422,824	421,994
Dividends per common share (in dollars per share)	$ 0.02	$ 0.01	$ 0.04	$ 0.03