SUPPLEMENTAL INFORMATION ON OIL AND NATURAL GAS OPERATIONS - UNAUDITED - Capitalized Costs and Accumulated Depreciation, Depletion and Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract]
Proved properties	$ 713,157
Unevaluated properties	102,187
Less: accumulated depreciation, depletion and amortization	(353,462)
Predecessor
Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract]
Proved properties		$ 9,616,236
Unevaluated properties		373,720
Less: accumulated depreciation, depletion and amortization		(9,178,442)
United States
Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract]
Proved properties	713,157
Unevaluated properties	102,187
Total proved and unevaluated properties	815,344
Less: accumulated depreciation, depletion and amortization	(353,462)
Net proved oil and gas properties	$ 461,882
United States | Predecessor
Capitalized Costs, Oil and Gas Producing Activities, Gross [Abstract]
Proved properties		9,572,082
Unevaluated properties		373,720
Total proved and unevaluated properties		9,945,802
Less: accumulated depreciation, depletion and amortization		(9,134,288)
Net proved oil and gas properties		$ 811,514