SEGMENT INFORMATION - Adjusted EBITDA by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 66,104	$ 75,188
Utica Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	7,719	5,928
Ohio Gathering
Segment Reporting Information [Line Items]
Adjusted EBITDA	6,872	7,939
Williston Basin
Segment Reporting Information [Line Items]
Adjusted EBITDA	10,805	16,192
DJ Basin
Segment Reporting Information [Line Items]
Adjusted EBITDA	5,347	5,911
Permian Basin
Segment Reporting Information [Line Items]
Adjusted EBITDA	709	1,581
Piceance Basin
Segment Reporting Information [Line Items]
Adjusted EBITDA	21,034	23,557
Barnett Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	8,016	8,760
Marcellus Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 5,602	$ 5,320