RESTRUCTURING AND OTHER RELATED CHARGES - Rollforward of Restructuring Liability (Details) - USD ($) $ in Thousands	7 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	May 31, 2015
Restructuring Cost and Reserve [Line Items]
Charges (credits), net	$ 0	$ 2,651	$ 5,513	$ 0
Furmanite Netherlands and Belgium Exit
Restructuring Cost and Reserve [Line Items]
Charges (credits), net		(1,229)	5,513
2017 Cost Savings Initiative
Restructuring Cost and Reserve [Line Items]
Charges (credits), net		3,880	0
Employee Severance | Furmanite Netherlands and Belgium Exit
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		4,846	0
Charges (credits), net		(173)	4,846
Payments		(3,144)	0
Disposal		(1,601)	0
Foreign currency adjustments		72	0
Balance, end of period	$ 0	0	4,846
Employee Severance | 2017 Cost Savings Initiative
Restructuring Cost and Reserve [Line Items]
Balance, beginning of period		0
Charges (credits), net		3,880
Payments		(3,292)
Balance, end of period		$ 588	$ 0