CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
OPERATING REVENUES
Natural gas	$ 323,319	$ 260,200	$ 1,152,089	$ 711,010
Crude oil and condensate	56,913	37,777	144,528	114,610
Gain (loss) on derivative instruments	(836)	6,904	46,353	(1,286)
Brokered natural gas	3,528	3,641	12,260	9,417
Other	2,492	1,907	8,486	5,435
TOTAL OPERATING REVENUES	385,416	310,429	1,363,716	839,186
OPERATING EXPENSES
Direct operations	26,282	24,626	78,185	77,139
Transportation and gathering	117,891	105,671	361,909	322,883
Brokered natural gas	2,797	2,939	10,262	7,526
Taxes other than income	9,194	8,771	26,562	23,737
Exploration	6,466	2,988	16,623	13,109
Depreciation, depletion and amortization	146,267	139,490	425,689	448,910
Impairment of oil and gas properties	0	0	68,555	0
General and administrative	23,244	19,374	70,902	67,192
TOTAL OPERATING EXPENSES	332,141	303,859	1,058,687	960,496
Earnings (loss) on equity method investments	(1,417)	(1,727)	(3,986)	208
Loss on sale of assets	(11,872)	(1,245)	(13,498)	(768)
INCOME (LOSS) FROM OPERATIONS	39,986	3,598	287,545	(121,870)
Interest expense, net	20,331	21,483	61,720	67,821
Loss on debt extinguishment	0	0	0	4,709
Other expense (income)	(5,083)	402	(4,974)	1,207
Income (loss) before income taxes	24,738	(18,287)	230,799	(195,607)
Income tax expense (benefit)	7,151	(8,027)	85,965	(71,243)
NET INCOME (LOSS)	$ 17,587	$ (10,260)	$ 144,834	$ (124,364)
Earnings (loss) per share
Basic (in dollars per share)	$ 0.04	$ (0.02)	$ 0.31	$ (0.27)
Diluted (in dollars per share)	$ 0.04	$ (0.02)	$ 0.31	$ (0.27)
Weighted-average common shares outstanding
Basic (in shares)	462,498	465,149	464,194	454,060
Diluted (in shares)	464,780	465,149	466,010	454,060
Dividends per common share (in dollars per share)	$ 0.05	$ 0.02	$ 0.12	$ 0.06