REVENUE (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) region	Jun. 30, 2019 USD ($) region	Jun. 30, 2020 USD ($) segment region	Jun. 30, 2019 USD ($) region
REVENUE
Number of Reportable Segments | segment			3
Revenue	$ 92,239	$ 323,887	$ 370,524	$ 686,533
Permian Basin
REVENUE
Revenue	36,638	148,118	174,636	310,783
Eagle Ford
REVENUE
Revenue	10,672	41,033	46,336	79,759
Haynesville/E. Texas
REVENUE
Revenue	14,708	18,314	33,723	35,596
Marcellus/Utica
REVENUE
Revenue	13,251	28,292	33,090	58,451
MidCon
REVENUE
Revenue	7,825	48,515	32,698	106,978
Rockies
REVENUE
Revenue	6,927	21,494	25,796	43,936
Bakken
REVENUE
Revenue	2,542	20,361	25,102	46,143
All other
REVENUE
Revenue	$ (324)	$ (2,240)	$ (857)	$ 4,887
Permian Basin, Eagle Ford and Marcellus/Utica | Water Services
REVENUE
Number of revenue producing regions | region	3	3	3	3
Percentage of revenue	69.00%	72.00%	73.00%	72.00%
Permian Basin and Bakken | Water Infrastructure
REVENUE
Number of revenue producing regions | region	2	2	2	2
Percentage of revenue	82.00%	81.00%	86.00%	82.00%
Permian Basin, Haynesville/E. Texas and MidCon | Oilfield Chemicals
REVENUE
Number of revenue producing regions | region	3	3	3	3
Percentage of revenue	89.00%	87.00%	83.00%	87.00%