FRESH START ACCOUNTING (Reorganization Adjustments and Fresh Start Adjustments) (Details) - USD ($) $ / shares in Units, $ in Thousands	5 Months Ended	7 Months Ended	12 Months Ended
	May 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 04, 2018
Cash and Cash Equivalents [Abstract]
Funding of the professional fees escrow account	$ (7,650)
Payment of debt issuance costs on the Successor Exit Credit Facility	(2,813)
Payment of professional fees	(1,591)	$ (2,323)
Payment of success fees	(1,573)
Payment of derivative settlement	(216)
Payment of accrued interest payable under the Predecessor credit facility	(135)
Transfer of funds from Predecessor's general partner	40
Changes in cash and cash equivalents	(13,938)
Cancellation of Related party claims	200
Accounts Payable and Accrued Liabilities [Abstract]
Recognition of payables for success fees	4,086
Recognition of payables for professional fees	32
Payment of professional fees	(1,590)
Payment of derivative settlement	(216)
Payment of accrued interest payable under the Predecessor credit facility	(135)
Net increase in accounts payable and accrued liabilities	2,177	513
Borrowings under credit facility reclassified to long-term debt	297,000	115,000
Disallowed interest payable not included in accrued interest payable	4,700
Liabilities Subject to Compromise [Abstract]
Senior Notes	343,348
Accrued interest payable	12,718
Total liabilities subject to compromise of Predecessor	356,066
Issuance of common stock to holders of the Senior Notes	(227,366)
Gain on settlement of liabilities subject to compromise	128,700
Contributions from general partner	$ 40
Successor common stock, shares issued	10,000,016
Common Stock, Par or Stated Value Per Share	$ 0.01				$ 0.01
Number of warrants issued	800,000
Fair value of warrants per share	$ 11.68
Stockholders’ / owners’ equity:
Issuance of successor commons stock to predecessor equity, value	$ 100
Additional paid-in capital from issuance of Successor common stock	239,233
Additional paid-in capital from issuance of Successor warrants	9,345
Fair value of successor equity	248,678	273,539
Proved oil and natural gas properties	547,136	410,184
Unproved oil and natural gas properties	68,882	8,454
Total oil and natural gas properties	616,018	418,638
Accumulated depreciation, depletion and amortization		(12,950)
Oil and Gas Property, Successful Effort Method, Net, Total	616,018	$ 405,688
Decrease in asset retirement obligations	(42,000)
Predecessor
Cash and Cash Equivalents [Abstract]
Payment of professional fees	(13,345)
Transfer of funds from Predecessor's general partner	40
Deferred financing cost related to credit facility	800
Accounts Payable and Accrued Liabilities [Abstract]
Net increase in accounts payable and accrued liabilities	(4,405)		$ 6,783	$ 5,862
Borrowings under credit facility reclassified to long-term debt			605,549
Liabilities Subject to Compromise [Abstract]
Gain on settlement of liabilities subject to compromise	128,700
Contributions from general partner	40
Issuance of common stock to Predecessor common unitholders	11,967
Issuance of warrants to Predecessor common unitholders	9,345
Stockholders’ / owners’ equity:
Proved oil and natural gas properties	2,593,249		2,567,086
Total oil and natural gas properties	2,593,249		2,567,086
Accumulated depreciation, depletion and amortization	(1,237,745)		(1,191,559)
Oil and Gas Property, Successful Effort Method, Net, Total	1,355,504		$ 1,375,527
Successor
Cash and Cash Equivalents [Abstract]
Deferred financing cost related to credit facility	2,800
Liabilities Subject to Compromise [Abstract]
Successor common stock, shares issued		10,054,816
Common Stock, Par or Stated Value Per Share		$ 0.01
Stockholders’ / owners’ equity:
Accumulated depreciation, depletion and amortization		$ (12,950)
General Partner Interest
Cash and Cash Equivalents [Abstract]
Transfer of funds from Predecessor's general partner	40
Liabilities Subject to Compromise [Abstract]
Gain on settlement of liabilities subject to compromise	2,426
Contributions from general partner	40
Cancellation of Predecessor common unitholders / general partner interest	32,454
Net impact to accumulated deficit	34,920
Common Unitholders
Liabilities Subject to Compromise [Abstract]
Gain on settlement of liabilities subject to compromise	118,940
Issuance of common stock to Predecessor common unitholders	(11,967)
Issuance of warrants to Predecessor common unitholders	(9,345)
Cancellation of Predecessor common unitholders / general partner interest	(32,453)
Net impact to accumulated deficit	$ 65,175