SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Narrative) (Details)	3 Months Ended	5 Months Ended	7 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($)	May 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) customer	Dec. 31, 2018 USD ($) customer	Dec. 31, 2017 USD ($) customer	Dec. 31, 2016 USD ($)	Jun. 04, 2018 USD ($)	Jun. 01, 2018 USD ($)	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Financial Designation, Predecessor and Successor [Fixed List]		Predecessor	Successor	Successor	Successor	Predecessor	Predecessor
Allowance for doubtful accounts receivable			$ 0	$ 0	$ 0
Doubtful accounts receivable, related expenses				0	0	$ 0
Capitalized costs associated with unproved properties			8,500,000	500,000	8,500,000
Impairment of oil and natural gas properties	$ 129,100,000	$ 3,000	3,065,000	129,082,000		93,607,000
Cash and cash equivalents		35,020,000	6,313,000	28,968,000	6,313,000			$ 21,082,000	$ 21,082,000
Cash and cash equivalents and restricted cash		28,732,000	6,313,000	38,968,000	6,313,000	4,896,000	$ 57,633,000
Net cash (used in) provided by investing activities		(29,046,000)	114,279,000	171,612,000		(82,437,000)
Other assets		4,507,000	4,474,000	4,965,000	4,474,000				$ 5,447,000
Override Royalty Based Partnership [Member]
Significant Accounting Policies [Line Items]
Override royalty (ORRI) percentage contributed to limited partnership										7.50%
Equity Method Investment, Ownership Percentage										48.00%
Partnership interest of gross revenues from underlying properties of partnership.										5.64%
Other assets			100,000	1,400,000	$ 100,000
Equity in (loss) income of unconsolidated affiliates		$ 100,000	200,000	2,900,000		500,000
Barnett Shale [Member]
Significant Accounting Policies [Line Items]
Impairment of oil and natural gas properties				78,100,000
San Juan Property [Member]
Significant Accounting Policies [Line Items]
Impairment of oil and natural gas properties				25,400,000
Permian Basin Property [Member]
Significant Accounting Policies [Line Items]
Impairment of oil and natural gas properties				8,000,000
Monroe Field Property [Member]
Significant Accounting Policies [Line Items]
Impairment of oil and natural gas properties				$ 2,100,000
Unproved oil and natural gas properties
Significant Accounting Policies [Line Items]
Impairment of oil and natural gas properties			$ 0			$ 23,700,000
Customer Concentration Risk | Sales Revenue, Goods, Net [Member]
Significant Accounting Policies [Line Items]
Concentration risk, number of clients | customer				3	1	2
Major Customer One [Member] | Customer Concentration Risk | Sales Revenue, Goods, Net [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage				17.40%	15.50%	15.50%
Major Customer Two [Member] | Customer Concentration Risk | Sales Revenue, Goods, Net [Member]
Significant Accounting Policies [Line Items]
Concentration risk, percentage				11.40%		11.00%
Major Customer Three [Member] | Customer Concentration Risk
Significant Accounting Policies [Line Items]
Concentration risk, percentage				10.10%
Minimum
Significant Accounting Policies [Line Items]
Estimated economic lives of other property				3 years
Maximum
Significant Accounting Policies [Line Items]
Estimated economic lives of other property				25 years