SUMMARY OF SIGNIFCANT ACCOUNTING POLICIES - Impairment (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2021	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Asset impairment charges	$ 400			$ 441	$ 1,643	$ 1,300,719
Gathering, processing, and transmission systems and facilities
Property, Plant and Equipment [Line Items]
Asset impairment charges		$ 1,300,000				1,300,000
Construction in progress
Property, Plant and Equipment [Line Items]
Asset impairment charges			$ 9,300			$ 9,300