RESTRUCTURING AND OTHER RELATED CHARGES - Rollforward of Restructuring Liability - Furmanite Belgium and Netherlands Exit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 1,676	$ 6,727	$ 2,651
Furmanite Netherlands and Belgium Exit
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 0	0	(1,229)
Furmanite Netherlands and Belgium Exit | Employee Severance
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		$ 0	4,846
Restructuring and other related charges (credits), net			(173)
Payments			(3,144)
Disposal			(1,601)
Foreign currency adjustments			72
Balance, end of period			$ 0