CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
OPERATING REVENUES
Operating revenues	$ 548,710	$ 386,252	$ 1,473,475	$ 1,317,363
Gain (loss) on derivative instruments	(3,537)	(836)	(1,628)	46,353
TOTAL OPERATING REVENUES	545,173	385,416	1,471,847	1,363,716
OPERATING EXPENSES
Direct operations	17,030	26,282	52,757	78,185
Taxes other than income	2,852	9,194	15,434	26,562
Exploration	10,049	6,466	68,166	16,623
Depreciation, depletion and amortization	121,172	146,267	288,210	425,689
Impairment of oil and gas properties	0	0	0	68,555
General and administrative	20,724	23,244	66,013	70,902
TOTAL OPERATING EXPENSES	394,766	332,141	1,024,865	1,058,687
Loss on equity method investments	(11)	(1,417)	(1,009)	(3,986)
Gain (loss) on sale of assets	25,655	(11,872)	(14,850)	(13,498)
INCOME FROM OPERATIONS	176,051	39,986	431,123	287,545
Interest expense, net	14,191	20,331	57,577	61,720
Other expense (income)	115	(5,083)	347	(4,974)
Income before income taxes	161,745	24,738	373,199	230,799
Income tax expense	39,408	7,151	91,201	85,965
NET INCOME	$ 122,337	$ 17,587	$ 281,998	$ 144,834
Earnings per share
Basic (in dollars per share)	$ 0.28	$ 0.04	$ 0.63	$ 0.31
Diluted (in dollars per share)	$ 0.28	$ 0.04	$ 0.62	$ 0.31
Weighted-average common shares outstanding
Basic (in shares)	440,772	462,498	450,445	464,194
Diluted (in shares)	443,110	464,780	452,313	466,010
Dividends per common share (in dollars per share)	$ 0.06	$ 0.05	$ 0.18	$ 0.12
Natural gas
OPERATING REVENUES
Operating revenues	$ 440,835	$ 323,319	$ 1,217,603	$ 1,152,089
Crude oil and condensate
OPERATING REVENUES
Operating revenues	0	56,913	48,722	144,528
Brokered natural gas
OPERATING REVENUES
Operating revenues	105,849	3,528	203,375	12,260
OPERATING EXPENSES
Operating expenses	93,405	2,797	178,437	10,262
Other
OPERATING REVENUES
Operating revenues	2,026	2,492	3,775	8,486
Transportation and gathering
OPERATING EXPENSES
Operating expenses	$ 129,534	$ 117,891	$ 355,848	$ 361,909