REVENUE - Schedule of Disaggregated Revenue by Geographic Area and Major Products and Services Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation Of Revenue [Line Items]
Total revenues	$ 99,318	$ 104,903
All Other Segments
Disaggregation Of Revenue [Line Items]
Total revenues	643	643
Reportable Segments
Disaggregation Of Revenue [Line Items]
Total revenues	98,675	104,260
Reportable Segments | Utica Shale
Disaggregation Of Revenue [Line Items]
Total revenues	8,572	6,962
Reportable Segments | Williston Basin
Disaggregation Of Revenue [Line Items]
Total revenues	29,366	31,263
Reportable Segments | DJ Basin
Disaggregation Of Revenue [Line Items]
Total revenues	7,077	7,959
Reportable Segments | Permian Basin
Disaggregation Of Revenue [Line Items]
Total revenues	8,833	7,010
Reportable Segments | Piceance Basin
Disaggregation Of Revenue [Line Items]
Total revenues	27,814	29,257
Reportable Segments | Barnett Shale
Disaggregation Of Revenue [Line Items]
Total revenues	10,812	15,574
Reportable Segments | Marcellus Shale
Disaggregation Of Revenue [Line Items]
Total revenues	6,201	6,235
Gathering Services and Related Fees
Disaggregation Of Revenue [Line Items]
Total revenues	70,348	83,792
Gathering Services and Related Fees | All Other Segments
Disaggregation Of Revenue [Line Items]
Total revenues	0	0
Gathering Services and Related Fees | Reportable Segments
Disaggregation Of Revenue [Line Items]
Total revenues	70,348	83,792
Gathering Services and Related Fees | Reportable Segments | Utica Shale
Disaggregation Of Revenue [Line Items]
Total revenues	8,572	6,962
Gathering Services and Related Fees | Reportable Segments | Williston Basin
Disaggregation Of Revenue [Line Items]
Total revenues	12,633	23,797
Gathering Services and Related Fees | Reportable Segments | DJ Basin
Disaggregation Of Revenue [Line Items]
Total revenues	6,263	6,855
Gathering Services and Related Fees | Reportable Segments | Permian Basin
Disaggregation Of Revenue [Line Items]
Total revenues	2,199	2,311
Gathering Services and Related Fees | Reportable Segments | Piceance Basin
Disaggregation Of Revenue [Line Items]
Total revenues	24,784	27,189
Gathering Services and Related Fees | Reportable Segments | Barnett Shale
Disaggregation Of Revenue [Line Items]
Total revenues	9,696	10,443
Gathering Services and Related Fees | Reportable Segments | Marcellus Shale
Disaggregation Of Revenue [Line Items]
Total revenues	6,201	6,235
Natural Gas, NGLs and Condensate Sales
Disaggregation Of Revenue [Line Items]
Total revenues	20,763	13,780
Natural Gas, NGLs and Condensate Sales | All Other Segments
Disaggregation Of Revenue [Line Items]
Total revenues	0	0
Natural Gas, NGLs and Condensate Sales | Reportable Segments
Disaggregation Of Revenue [Line Items]
Total revenues	20,763	13,780
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Utica Shale
Disaggregation Of Revenue [Line Items]
Total revenues	0	0
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Williston Basin
Disaggregation Of Revenue [Line Items]
Total revenues	12,227	4,324
Natural Gas, NGLs and Condensate Sales | Reportable Segments | DJ Basin
Disaggregation Of Revenue [Line Items]
Total revenues	110	70
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Permian Basin
Disaggregation Of Revenue [Line Items]
Total revenues	6,518	4,512
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Piceance Basin
Disaggregation Of Revenue [Line Items]
Total revenues	1,853	1,003
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Barnett Shale
Disaggregation Of Revenue [Line Items]
Total revenues	55	3,871
Natural Gas, NGLs and Condensate Sales | Reportable Segments | Marcellus Shale
Disaggregation Of Revenue [Line Items]
Total revenues	0	0
Other Revenues
Disaggregation Of Revenue [Line Items]
Total revenues	8,207	7,331
Other Revenues | All Other Segments
Disaggregation Of Revenue [Line Items]
Total revenues	643	643
Other Revenues | Reportable Segments
Disaggregation Of Revenue [Line Items]
Total revenues	7,564	6,688
Other Revenues | Reportable Segments | Utica Shale
Disaggregation Of Revenue [Line Items]
Total revenues	0	0
Other Revenues | Reportable Segments | Williston Basin
Disaggregation Of Revenue [Line Items]
Total revenues	4,506	3,142
Other Revenues | Reportable Segments | DJ Basin
Disaggregation Of Revenue [Line Items]
Total revenues	704	1,034
Other Revenues | Reportable Segments | Permian Basin
Disaggregation Of Revenue [Line Items]
Total revenues	116	187
Other Revenues | Reportable Segments | Piceance Basin
Disaggregation Of Revenue [Line Items]
Total revenues	1,177	1,065
Other Revenues | Reportable Segments | Barnett Shale
Disaggregation Of Revenue [Line Items]
Total revenues	1,061	1,260
Other Revenues | Reportable Segments | Marcellus Shale
Disaggregation Of Revenue [Line Items]
Total revenues	$ 0	$ 0