CRUDE OIL AND NATURAL GAS PROPERTIES - Fair Values of the Net Assets and Liabilities as of the Date of Acquisition (Details) - USD ($) $ / shares in Units, $ in Thousands	Jul. 01, 2019	Mar. 31, 2020	Dec. 31, 2019
Fair value of net assets:
Proved oil and natural gas properties		$ 4,265,534	$ 4,178,605
VEN Bakken LLC
Fair value of net assets:
Proved oil and natural gas properties	$ 324,974
Asset retirement cost	2,680
Total assets acquired	327,654
Asset retirement obligations	(2,680)
Derivative instruments	(9,694)
Net assets acquired	315,280
Fair value of consideration paid for net assets:
Cash consideration	174,912
Issuance of common stock	11,708
Unsecured VEN Bakken Note	128,660
Total fair value of consideration transferred	$ 315,280
Issuance of common stock (in shares)	5,602,147
Share price at issuance (in dollars per share)	$ 2.09