Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues:
Net (loss) gain on natural gas, oil, and NGL derivatives	$ (123,479,000)	$ 213,679,000	$ (174,506,000)
Total revenues	1,355,044,000	1,320,303,000	385,910,000
Costs and expenses:
Lease operating expenses	91,640,000	80,246,000	68,877,000
Production taxes	33,480,000	21,126,000	13,276,000
Midstream gathering and processing expenses	290,188,000	248,995,000	165,972,000
Depreciation, depletion and amortization	486,664,000	364,629,000	245,974,000
Impairment of oil and natural gas properties	0	0	715,495,000
General and administrative expenses	56,633,000	52,938,000	43,409,000
Accretion expense	4,119,000	1,611,000	1,057,000
Acquisition expense	0	2,392,000	0
Total costs and expenses	962,724,000	771,937,000	1,254,060,000
INCOME (LOSS) FROM OPERATIONS	392,320,000	548,366,000	(868,150,000)
OTHER (INCOME) EXPENSE:
Interest expense	135,273,000	108,198,000	63,530,000
Interest income	(314,000)	(1,009,000)	(1,230,000)
Litigation settlement	1,075,000	0	0
Insurance proceeds	(231,000)	0	(5,718,000)
Loss on debt extinguishment	0	0	23,776,000
Gain on sale of equity method investments	(124,768,000)	(12,523,000)	(3,391,000)
(Income) loss from equity method investments, net	(49,904,000)	17,780,000	37,376,000
Other expense (income), net	698,000	(1,041,000)	129,000
Total Other (Income) Expense	(38,171,000)	111,405,000	114,472,000
INCOME (LOSS) BEFORE INCOME TAXES	430,491,000	436,961,000	(982,622,000)
INCOME TAX (BENEFIT) EXPENSE	(69,000)	1,809,000	(2,913,000)
NET INCOME (LOSS)	$ 430,560,000	$ 435,152,000	$ (979,709,000)
NET INCOME (LOSS) PER COMMON SHARE:
Basic (usd per share)	$ 2.46	$ 2.42	$ (7.97)
Diluted (usd per share)	$ 2.45	$ 2.41	$ (7.97)
Weighted average common shares outstanding - Basic (shares)	174,675,840	179,834,146	122,952,866
Weighted average common shares outstanding - Diluted (shares)	175,398,706	180,253,024	122,952,866
Natural gas sales
Revenues:
Revenue from contracts with customers	$ 1,121,815,000	$ 845,999,000	$ 420,128,000
Oil and condensate sales
Revenues:
Revenue from contracts with customers	177,793,000	124,568,000	81,173,000
Natural gas liquid sales
Revenues:
Revenue from contracts with customers	$ 178,915,000	$ 136,057,000	$ 59,115,000