CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
OPERATING REVENUES
Natural gas	$ 227,578	$ 360,191
Crude oil and condensate	30,676	62,558
Gain (loss) on derivative instruments	18,994	34,123
Brokered natural gas	3,180	4,827
Other	1,513	3,066
TOTAL OPERATING REVENUES	281,941	464,765
OPERATING EXPENSES
Direct operations	26,035	36,017
Transportation and gathering	109,652	121,235
Brokered natural gas	2,566	3,739
Taxes other than income	5,994	11,280
Exploration	6,383	8,732
Depreciation, depletion and amortization	161,887	175,497
General and administrative	28,376	22,529
TOTAL OPERATING EXPENSES	340,893	379,029
Earnings (loss) on equity method investments	2,009	1,421
Gain (loss) on sale of assets	1,354	138
INCOME (LOSS) FROM OPERATIONS	(55,589)	87,295
Interest expense	24,375	23,566
Income (loss) before income taxes	(79,964)	63,729
Income tax expense (benefit)	(28,770)	23,474
NET INCOME (LOSS)	$ (51,194)	$ 40,255
Earnings (loss) per share
Basic (in dollars per share)	$ (0.12)	$ 0.10
Diluted (in dollars per share)	$ (0.12)	$ 0.10
Weighted-average common shares outstanding
Basic (in shares)	431,841	413,344
Diluted (in shares)	431,841	414,771
Dividends per common share (in dollars per share)	$ 0.02	$ 0.02