ESTIMATED PROVED OIL, NATURAL GAS AND NATURAL GAS LIQUIDS RESERVES (UNAUDITED) (Changes in Estimated Proved and Estimated Proved Developed Reserves) (Details)			12 Months Ended
		Jun. 04, 2018 Bcfe	Dec. 31, 2018 Bcfe Mcfe Mcf MBbls	Dec. 31, 2017 Bcfe Mcfe Mcf MBbls		Dec. 31, 2016 Bcfe Mcfe Mcf MBbls		Dec. 31, 2015 Mcfe Mcf MBbls
Reserve Quantities [Line Items]
Revisions of previous estimates, energy | Mcfe	[1],[2]		62,600
Extensions and discoveries, energy | Mcfe	[1],[3]		4,859
Production, energy | Mcfe	[1]		(62,222)
Sales of minerals in place, energy | Mcfe	[1],[4]		(106,994)
Proved developed and undeveloped reserves, ending balance, energy | Mcfe	[1]		711,870
Proved developed reserves (energy) | Mcfe	[1]		698,445
Proved undeveloped reserves (energy) | Mcfe	[1]		13,425
Predecessor
Reserve Quantities [Line Items]
Proved developed and undeveloped reserves, beginning balance, energy | Mcfe	[1]		813,627	851,219		1,096,753
Revisions of previous estimates, energy | Mcfe	[1]			7,867	[5]	(114,041)	[6]
Purchase of minerals in place, energy | Mcfe	[1]			16,444
Extensions and discoveries, energy | Mcfe	[1]			6,053	[7]	15,038	[8]
Production, energy | Mcfe	[1]			(62,293)		(70,612)
Sales of minerals in place, energy | Mcfe	[1]			(5,663)	[9]	(75,919)	[10]
Proved developed and undeveloped reserves, ending balance, energy | Mcfe	[1]			813,627		851,219
Proved developed reserves (energy) | Mcfe	[1]			813,627		764,149		909,047
Proved undeveloped reserves (energy) | Mcfe	[1]					87,070		187,706
Proved undeveloped reserves | Predecessor
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe				(85.0)
Oil
Reserve Quantities [Line Items]
Revisions of previous estimates	[2],[11]		4,640
Extensions and discoveries	[3],[11]		7
Production	[11]		(1,304)
Sales of minerals in place	[4],[11]		(6,823)
Proved developed and undeveloped reserves, ending balance	[11]		9,913
Proved developed reserves (volume)	[11]		9,881
Proved undeveloped reserve (volume)	[11]		32
Oil | Predecessor
Reserve Quantities [Line Items]
Proved developed and undeveloped reserves, beginning balance	[11]		13,393	12,592		21,995
Revisions of previous estimates	[11]			1,141	[5]	(8,163)	[6]
Purchases of minerals in place	[11]			1,228
Extensions and discoveries	[11]			105	[7]	61	[8]
Production	[11]			(1,387)		(1,216)
Sales of minerals in place	[11]			(286)	[9]	(85)	[10]
Proved developed and undeveloped reserves, ending balance	[11]			13,393		12,592
Proved developed reserves (volume)	[11]			13,393		11,954		13,919
Proved undeveloped reserve (volume)	[11]					638		8,076
Natural Gas [Member]
Reserve Quantities [Line Items]
Revisions of previous estimates | Mcf	[2],[12]		7,641
Extensions and discoveries | Mcf	[3],[12]		4,192
Production | Mcf	[12]		(40,066)
Sales of minerals in place | Mcf	[4],[12]		(38,785)
Proved developed and undeveloped reserves, ending balance | Mcf	[12]		476,688
Proved developed reserves (volume) | Mcf	[12]		468,510
Proved undeveloped reserve (volume) | Mcf	[12]		8,178
Natural Gas [Member] | Predecessor
Reserve Quantities [Line Items]
Proved developed and undeveloped reserves, beginning balance | Mcf	[12]		543,706	575,298		747,015
Revisions of previous estimates | Mcf	[12]			3,558	[5]	(57,723)	[6]
Purchases of minerals in place | Mcf	[12]			6,578
Extensions and discoveries | Mcf	[12]			3,035	[7]	10,255	[8]
Production | Mcf	[12]			(40,979)		(49,333)
Sales of minerals in place | Mcf	[12]			(3,784)	[9]	(74,916)	[10]
Proved developed and undeveloped reserves, ending balance | Mcf	[12]			543,706		575,298
Proved developed reserves (volume) | Mcf	[12]			543,706		523,113		644,984
Proved undeveloped reserve (volume) | Mcf	[12]					52,185		102,031
Natural Gas Liquids [Member]
Reserve Quantities [Line Items]
Revisions of previous estimates	[2],[11]		4,518
Extensions and discoveries	[3],[11]		104
Production	[11]		(2,388)
Sales of minerals in place	[4],[11]		(4,544)
Proved developed and undeveloped reserves, ending balance	[11]		29,284
Proved developed reserves (volume)	[11]		28,442
Proved undeveloped reserve (volume)	[11]		842
Natural Gas Liquids [Member] | Predecessor
Reserve Quantities [Line Items]
Proved developed and undeveloped reserves, beginning balance	[11]		31,594	33,395		36,294
Revisions of previous estimates	[11]			(422)	[5]	(1,223)	[6]
Purchases of minerals in place	[11]			415
Extensions and discoveries	[11]			398	[7]	736	[8]
Production	[11]			(2,165)		(2,331)
Sales of minerals in place	[11]			(27)	[9]	(81)	[10]
Proved developed and undeveloped reserves, ending balance	[11]			31,594		33,395
Proved developed reserves (volume)	[11]			31,594		28,218		30,091
Proved undeveloped reserve (volume)	[11]					5,177		6,203
Barnett Shale | Predecessor
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe						74,200,000,000
Increase (decrease) in oil and natural gas reserves | Bcfe						(39.9)
Central Texas [Member] | Predecessor
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe						(13.5)
Appalachian Basin and San Juan Basin [Member]
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe			(20.8)
Mid Continent Property [Member]
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe			800,000,000
Mid Continent Property [Member] | Predecessor
Reserve Quantities [Line Items]
Volume produced from oil drilling success | Bcfe				1,500,000,000
Central Texas Property
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe			(106,100,000,000)
Central Texas Property | Predecessor
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe				600,000,000
Barnette Shale Property
Reserve Quantities [Line Items]
Volume produced from oil drilling success | Bcfe			4,800,000,000
Barnette Shale Property | Predecessor
Reserve Quantities [Line Items]
Volume produced from oil drilling success | Bcfe				4,200,000,000		13,000,000,000
Appalachain Basin Property [Member] | Predecessor
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe				(4,600,000,000)
Appalachain Basin Property [Member] | Appalachian Basin | Predecessor
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe						(51.8)
San Juan Property [Member] | Predecessor
Reserve Quantities [Line Items]
Sales of minerals in place, energy | Bcfe				500,000,000
SEC Pricing [Member]
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe		66.7	24.3
SEC Pricing [Member] | Predecessor
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe				81.8
Other Various Revisions Aggregated [Member]
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe			(7.6)
Other Various Revisions Aggregated [Member] | Predecessor
Reserve Quantities [Line Items]
Increase (decrease) in oil and natural gas reserves | Bcfe				11.0

[1] Million cubic feet equivalent; barrels are converted to Mcfe based on one barrel of oil or natural gas liquids to six Mcf of natural gas equivalent.

[2] Revisions were attributable to a combination of reserve increases (66.7 Bcfe) resulting from our emergence from bankruptcy on June 4, 2018 and the availability of capital required to develop the PUDs within the SEC five-year development limitation on PUDs, reserve increases (24.3 Bcfe) resulting from improvements in SEC pricing from December 31, 2017 to December 31, 2018, reductions (20.8 Bcfe) primarily due to negative revisions in Appalachian and San Juan basins, and an aggregate decrease (7.6 Bcfe) from various other revisions.

[3] Extensions and discoveries were primarily associated with drilling success in the Barnett Shale (4.8 Bcfe).

[4] Sales of minerals in place were primarily associated with the sale of all properties in Central Texas (106.1 Bcfe) with smaller sales in the Mid-Continent area (0.8 Bcfe) and other areas.

[5] Revisions were attributable to a combination of reserve increases (81.8 Bcfe) resulting from improvements in SEC pricing from December 31, 2016 to December 31, 2017, reductions (85.0 Bcfe) due to the removal of all PUD reserves and an aggregate increase from various other revisions (11.0 Bcfe).

[6] Revisions were primarily attributable to reductions in the Appalachian Basin (51.8 Bcfe), the Barnett Shale (39.9 Bcfe) and Central Texas (13.5 Bcfe) and were the result of the decrease in prices for oil, natural gas and natural gas liquids used in the December 31, 2016 reserve estimates from prices used in the December 31, 2015 reserve estimates.

[7] Extensions and discoveries were primarily associated with drilling success in the Barnett Shale (4.2 Bcfe) and Mid-Continent area (1.5 Bcfe).

[8] Extensions and discoveries were primarily associated with drilling success in the Barnett Shale (13.0 Bcfe).

[9] Sales of minerals in place were primarily associated with the sale of properties in the Appalachian Basin (4.6 Bcfe), Central Texas (0.6 Bcfe) and San Juan Basin (0.5 Bcfe).

[10] Sales of minerals in place were primarily associated with the sale of a portion of the Barnett Shale natural gas properties (74.2 Bcfe) in December 2016.

[11] Thousands of barrels.

[12] Million cubic feet.