SUPPLEMENTAL INFORMATION ON OIL AND NATURAL GAS OPERATIONS - UNAUDITED - Financial Data Related to Oil and Gas Producing Activities (Details) - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							10 Months Ended	12 Months Ended
	Mar. 31, 2017	Feb. 28, 2017	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated DD&A:
Foreign currency translation adjustment										$ 0
Write-down of oil and gas properties	$ (256,435)		$ 0	$ 0	$ 0					(256,435)
Balance, end of year			(353,462)							(353,462)	$ (353,462)
Costs incurred during the period (expensed):
Lease operating expenses										49,800
Transportation, processing and gathering expenses										4,084
Production taxes										629
Accretion expense										21,151
United States
Costs incurred during the period (capitalized):
Acquisition costs, net of sales of unevaluated properties										(8,371)
Exploratory costs										12,079
Development costs										33,356
Salaries, general and administrative costs										7,495
Interest										3,927
Less: overhead reimbursements										(1,004)
Total costs incurred during the year										47,482
Balance, end of year (fully evaluated at December 31, 2016 and 2015)			815,344							815,344	815,344
Accumulated DD&A:
Write-down of oil and gas properties										(256,435)
Balance, end of year			(353,462)							(353,462)	(353,462)
Net proved oil and gas properties			$ 461,882							461,882	461,882
Costs incurred during the period (expensed):
Lease operating expenses										49,800
Transportation, processing and gathering expenses										4,084
Production taxes										629
Accretion expense										21,151
Expensed costs – United States										$ 75,664
Predecessor
Accumulated DD&A:
Balance, beginning of year		$ (9,178,442)									(9,178,442)
Foreign currency translation adjustment		0										$ (6,073)	$ 2,605
Write-down of oil and gas properties		0				$ (73,094)	$ (36,484)	$ (118,649)	$ (129,204)			(357,431)	(1,362,447)
Balance, end of year						(9,178,442)						(9,178,442)
Costs incurred during the period (expensed):
Lease operating expenses		8,820										79,650	100,139
Transportation, processing and gathering expenses		6,933										27,760	58,847
Production taxes		682										3,148	6,877
Accretion expense		5,447										40,229	25,988
Predecessor | United States
Oil and gas properties – United States and Canada, proved and unevaluated:
Balance, beginning of year		9,945,802									9,945,802
Costs incurred during the period (capitalized):
Acquisition costs, net of sales of unevaluated properties		(324)										3,923	(14,158)
Exploratory costs		2,055										17,891	104,169
Development costs		12,547										102,665	266,982
Salaries, general and administrative costs		2,976										21,753	27,984
Interest		2,524										26,634	41,339
Less: overhead reimbursements		0										(521)	(913)
Total costs incurred during the year		19,778										172,345	425,403
Balance, end of year (fully evaluated at December 31, 2016 and 2015)						9,945,802						9,945,802
Accumulated DD&A:
Balance, beginning of year		(9,134,288)									(9,134,288)
Write-down of oil and gas properties											0	(357,079)	(1,314,817)
Balance, end of year						(9,134,288)						(9,134,288)
Net proved oil and gas properties						811,514						811,514
Costs incurred during the period (expensed):
Lease operating expenses		8,820										79,650	100,139
Transportation, processing and gathering expenses		6,933										27,760	58,847
Production taxes		682										3,148	6,877
Accretion expense		5,447										40,229	25,988
Expensed costs – United States		21,882										150,787	191,851
Predecessor | CANADA
Oil and gas properties – United States and Canada, proved and unevaluated:
Balance, beginning of year		44,154							42,484		44,154	42,484	36,579
Costs incurred during the period (capitalized):
Acquisition costs												(498)	(2,862)
Exploratory costs												2,168	8,767
Total costs incurred during the year												1,670	5,905
Balance, end of year (fully evaluated at December 31, 2016 and 2015)						44,154						44,154	42,484
Accumulated DD&A:
Balance, beginning of year		$ (44,154)							$ (42,484)		$ (44,154)	(42,484)	0
Foreign currency translation adjustment												(1,318)	5,146
Write-down of oil and gas properties												(352)	(47,630)
Balance, end of year						(44,154)						(44,154)	(42,484)
Net proved oil and gas properties						$ 0						$ 0	$ 0