SEGMENT INFORMATION - Reconciliation of Net Income to Adjusted EBITDA (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting [Abstract]
Loss before income taxes and loss from equity method investees	$ (36,266,000)	$ (5,402,000)
Add:
Corporate and Other expense	14,159,000	10,623,000
Interest expense	17,527,000	15,122,000
Deferred Purchase Price Obligation	4,427,000	21,658,000
Depreciation and amortization	28,116,000	26,526,000
Proportional adjusted EBITDA for equity method investees	9,210,000	10,477,000
Adjustments related to MVC shortfall payments	(4,199,000)	0
Adjustments related to capital reimbursement activity	(715,000)	40,000
Unit-based and noncash compensation	2,526,000	1,962,000
Gain on asset sales, net	(961,000)	(74,000)
Long-lived asset impairment	44,951,000	0
Total of reportable segments' measures of profit	$ 78,775,000	$ 80,932,000