CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues and other income:
Revenues and other income										$ 3,333,836
Derivative fair value (loss) income		$ 100,698	$ (34,591)	$ (103,290)	$ (14,009)	$ 25,024	$ (88,426)	$ 111,195	$ 165,557	(51,192)	$ 213,350	$ (261,391)
Total revenues and other income		1,072,637	811,225	656,184	742,599	679,032	482,232	673,111	776,655	3,282,645	2,611,030	1,099,939
Costs and expenses:
Production and ad valorem taxes		16,656	9,427	10,140	9,926	11,757	11,993	9,969	9,163	46,149	42,882	25,443
Brokered natural gas and marketing		221,626	116,080	102,747	55,594	51,131	59,773	55,857	53,550	496,047	220,311	168,576
Exploration		10,600	8,299	7,499	7,719	7,893	22,767	14,498	8,504	34,117	53,662	32,325
Abandonment and impairment of unproved properties		441,750	6,549	54,922	11,773	217,544	42,568	5,193	4,420	514,994	269,725	30,076
General and administrative		50,090	43,722	47,583	68,417	80,553	53,035	52,322	47,496	209,812	233,406	184,772
MRD Merger expenses										0	0	37,225
Termination costs		0	(336)	0	(37)	(279)	(47)	(96)	4,192	(373)	3,770	(519)
Deferred compensation plan		(18,072)	223	6,615	(7,397)	(14,077)	(9,203)	(14,466)	(13,169)	(18,631)	(50,915)	19,153
Interest		49,161	54,801	53,862	52,385	51,473	49,179	47,926	47,101	210,209	195,679	168,213
Depletion, depreciation and amortization		147,909	164,266	161,026	162,266	162,918	159,749	152,504	149,821	635,467	624,992	524,102
Impairment of proved properties		0	0	15,302	7,312	0	63,679	0	0	22,614	63,679	43,040
Impairment of goodwill		1,641,197	0	0	0					1,641,197	0	0
Loss (gain) on the sale of assets		10,815	30	(156)	(23)	(207)	(102)	(807)	(22,600)	10,666	(23,716)	7,074
Total costs and expenses		2,905,843	738,549	764,538	650,685	806,927	681,924	545,910	494,149	5,059,615	2,528,910	1,902,077
(Loss) income before income taxes		(1,833,206)	72,676	(108,354)	91,914	(127,895)	(199,692)	127,201	282,506	(1,776,970)	82,120	(802,138)
Income tax (benefit) expense:
Current		0	0	0	0	17	0	0	0	0	17	98
Deferred		(68,784)	24,137	(28,518)	42,676	(349,097)	(71,992)	57,651	112,395	(30,489)	(251,043)	(280,848)
Total (benefit) expense for income taxes		(68,784)	24,137	(28,518)	42,676	(349,080)	(71,992)	57,651	112,395	(30,489)	(251,026)	(280,750)
Net (loss) income		$ (1,764,422)	$ 48,539	$ (79,836)	$ 49,238	$ 221,185	$ (127,700)	$ 69,550	$ 170,111	$ (1,746,481)	$ 333,146	$ (521,388)
Net (loss) income per common share:
Basic		$ (7.15)	$ 0.19	$ (0.32)	$ 0.20	$ 0.89	$ (0.52)	$ 0.28	$ 0.69	$ (7.10)	$ 1.34	$ (2.75)
Diluted		$ (7.15)	$ 0.19	$ (0.32)	$ 0.20	$ 0.89	$ (0.52)	$ 0.28	$ 0.69	$ (7.10)	$ 1.34	$ (2.75)
Weighted average common shares outstanding:
Basic	[1]									246,171	245,091	189,868
Diluted										246,171	245,458	189,868
Natural Gas, NGLs and Oil Sales
Revenues and other income:
Revenues and other income		$ 756,627	$ 736,431	$ 661,390	$ 696,629	$ 603,159	$ 507,541	$ 506,137	$ 559,450	$ 2,851,077	$ 2,176,287	$ 1,197,215
Brokered Natural Gas, Marketing and Other
Revenues and other income:
Revenues and other income		215,312	109,385	98,084	59,979	50,849	63,117	55,779	51,648	482,760	221,393	164,115
Direct Operating
Costs and expenses:
Costs and expenses		35,395	30,926	35,088	38,122	37,921	36,888	31,420	28,023	139,531	134,252	97,388
Transportation, Gathering, Processing and Compression
Costs and expenses:
Costs and expenses		$ 298,716	$ 304,562	$ 269,910	$ 244,628	$ 200,300	$ 191,645	$ 191,590	$ 177,648	$ 1,117,816	$ 761,183	$ 565,209

[1] Includes common stock issued in connection with the exchange of 77.0 million shares for all outstanding Memorial common stock on September 16, 2016.