RESTRUCTURING AND OTHER RELATED CHARGES - Schedule of Restructuring Charges by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 6,727	$ 2,651	$ 5,513
OneTEAM Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	6,727
OneTEAM Program | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	6,727
OneTEAM Program | Employee Severance | IHT
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	2,995
OneTEAM Program | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	2,514
OneTEAM Program | Employee Severance | Quest Integrity
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	418
OneTEAM Program | Employee Severance | Corporate and shared support services
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 800
2017 Cost Savings Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		3,880
2017 Cost Savings Initiative | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		3,900
2017 Cost Savings Initiative | Employee Severance | IHT
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		966
2017 Cost Savings Initiative | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		1,622
2017 Cost Savings Initiative | Employee Severance | Quest Integrity
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		428
2017 Cost Savings Initiative | Employee Severance | Corporate and shared support services
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		864
Furmanite Netherlands and Belgium Exit
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		(1,229)	5,513
Furmanite Netherlands and Belgium Exit | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		(173)
Furmanite Netherlands and Belgium Exit | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		(173)	4,862
Furmanite Netherlands and Belgium Exit | Disposal (gain) loss & impairment | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net		$ (1,056)	$ 651