SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Settlement of prepaid expenses and other assets through noncash payments		$ 29,400,000
Allowance for doubtful accounts	$ 4,600,000	5,200,000
Provision for doubtful accounts	0	0	$ 700,000
Charged against the allowance for doubtful accounts	$ 700,000	300,000
Period for advance payments to be applied against joint interest billings	90 days
Impairment losses on non-crude oil and natural gas long-lived assets	$ 0
Minimum percentage of proved reserves sold to be considered a significant alteration	25.00%
Discount rate	10.00%
Capitalized costs related to expired leases subject to depletion	$ 3,600,000	9,400,000	18,700,000
Valuation allowance against deferred tax assets	144,198,000	123,734,000
Asset impairment charges	$ 0		0
Maximum percentage of annual contributions per employee	100.00%
Vested percentage	100.00%
Oil
Property, Plant and Equipment [Line Items]
Revenues	$ 574,600,000	450,100,000	204,600,000
Natural Gas and NGL
Property, Plant and Equipment [Line Items]
Revenues	$ 26,600,000	43,800,000	$ 19,400,000
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	3 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful lives	7 years
Other Noncurrent Assets
Property, Plant and Equipment [Line Items]
Accounts receivable	$ 4,700,000	$ 5,100,000