BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Gas And Oil Acreage [Line Items]
Number of reportable segments | segment	1
Operating lease right-of-use assets	$ 7,902	$ 0
Operating lease liabilities	8,000
ASU 2016–02
Gas And Oil Acreage [Line Items]
Operating lease right-of-use assets	9,900
Operating lease liabilities	$ 9,900