PROPERTY, PLANT, AND EQUIPMENT, NET - Schedule of Property, Plant, and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,258,749	$ 2,350,846
Less accumulated depreciation	384,820	387,133
Property, plant and equipment, net	1,873,929	1,963,713
Gathering and processing systems and related equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,025,055	2,155,325
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	169,987	137,920
Land and line fill
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	9,834	11,748
Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 53,873	$ 45,853