CONSOLIDATED STATEMENTS 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
Revenues and other income:
Natural gas, NGLs and oil sales	$ 431,214	$ 337,040	$ 1,267,131	$ 953,006
Derivative fair value (loss) income	(40,355)	(40,728)	(2,470)	47,008
Gain (loss) on the sale of assets	6,008	949	89,129	(12,704)
Brokered natural gas, marketing and other	45,171	2,519	80,843	12,356
Total revenues and other income	442,038	299,780	1,434,633	999,666
Costs and expenses:
Direct operating	30,907	29,628	93,731	85,691
Transportation, gathering and compression	60,958	51,600	189,422	137,164
Production and ad valorem taxes	11,454	8,819	33,950	57,239
Brokered natural gas and marketing	51,117	4,887	90,094	15,440
Exploration	20,496	14,752	50,344	51,785
Abandonment and impairment of unproved properties	11,692	40,118	46,066	104,048
General and administrative	44,919	44,497	230,964	127,231
Deferred compensation plan	(2,225)	20,052	33,257	21,555
Interest expense	44,321	43,997	131,602	124,090
Loss on early extinguishment of debt			12,280
Depletion, depreciation and amortization	130,343	123,059	365,439	332,012
Impairment of proved properties and other assets	7,012	1,281	7,753	1,281
Total costs and expenses	410,994	382,690	1,284,902	1,057,536
Income (loss) from operations before income taxes	31,044	(82,910)	149,731	(57,870)
Income tax expense (benefit)
Current
Deferred	11,866	(29,074)	62,180	(17,910)
Total income tax expense	11,866	(29,074)	62,180	(17,910)
Net income (loss)	$ 19,178	$ (53,836)	$ 87,551	$ (39,960)
Net income (loss) per common share:
Basic	$ 0.12	$ (0.34)	$ 0.54	$ (0.25)
Diluted	$ 0.12	$ (0.34)	$ 0.53	$ (0.25)
Dividends paid per common share	$ 0.04	$ 0.04	$ 0.12	$ 0.12
Weighted average common shares outstanding:
Basic	160,500	159,563	160,398	159,297
Diluted	161,374	159,563	161,321	159,297