GOODWILL AND OTHER INTANGIBLE ASSETS - Goodwill (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) segment
Goodwill
Number of Reporting Units | segment			1
Balance at the beginning of the period	$ 273,801	$ 266,934	$ 273,801
Measurement period adjustment			133
Affirm crane business divestiture			2,604
Impairment	0	(266,934)	(4,396)
Balance at the end of the period			266,934
Water Solutions
Goodwill
Balance at the beginning of the period	266,801		266,801
Resegmentation			(266,801)
Balance at the end of the period
Wellsite Services
Goodwill
Balance at the beginning of the period	$ 7,000		7,000
Resegmentation			(7,000)
Balance at the end of the period
Water Services
Goodwill
Balance at the beginning of the period		186,468
Resegmentation			186,335
Measurement period adjustment			133
Impairment		(186,468)
Balance at the end of the period			186,468
Water Infrastructure
Goodwill
Balance at the beginning of the period		80,466
Resegmentation			80,466
Impairment		$ (80,466)
Balance at the end of the period			80,466
Other
Goodwill
Resegmentation			7,000
Affirm crane business divestiture			2,604
Impairment			$ (4,396)