SUPPLEMENTARY INFORMATION ON OIL AND NATURAL GAS ACTIVITIES (UNAUDITED) (Capitalized Costs Relating to Oil and Natural Gas Producing Activities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Jun. 01, 2018	May 31, 2018
Supplementary Information On Oil And Natural Gas Activities [Abstract]
Proved oil and natural gas properties	$ 128,578	$ 410,184	$ 547,136	$ 2,593,249
Unproved oil and natural gas properties	519	8,454	68,882
Oil and natural gas properties, gross	129,097	418,638	616,018	2,593,249
Accumulated depreciation, depletion and amortization	(15,066)	(12,950)		(1,237,745)
Net capitalized costs	$ 114,031	$ 405,688	$ 616,018	$ 1,355,504

Supplementary Information On Oil And Natural Gas Activities [Abstract]

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Amount of accumulated depreciation, depletion and amortization of oil and gas property carried under the successful effort method. Oil and gas property include, but not limited to, the entity's wells and related equipment and facilities.

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Oil and Gas properties, gross, carried under the successful effort method.

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Oil and gas properties net of accumulated depreciation, depletion, amortization, impairment, and abandonment, carried under the successful effort method.

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Oil and Gas properties with proved reserves under the successful effort method.

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Oil and Gas properties with unproved reserves under the successful effort method.

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