RESTRUCTURING AND OTHER RELATED CHARGES - Schedule of Restructuring Charges by Segment (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
OneTEAM Program
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	1,676	6,727	0
OneTEAM Program | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	1,676	6,700
Severance charges incurred to date	8,400
OneTEAM Program | Employee Severance | IHT
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	249	2,995	0
OneTEAM Program | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	418	2,514	0
OneTEAM Program | Employee Severance | Quest Integrity
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	62	418	0
OneTEAM Program | Employee Severance | Corporate and shared support services
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	947	800	0
2017 Cost Savings Initiative
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	0	0	3,880
2017 Cost Savings Initiative | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net			3,900
Severance charges incurred to date	3,900
2017 Cost Savings Initiative | Employee Severance | IHT
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	0	0	966
2017 Cost Savings Initiative | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	0	0	1,622
2017 Cost Savings Initiative | Employee Severance | Quest Integrity
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	0	0	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	0	0	864
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]
Restructuring and other related charges (credits), net			(173)
Severance charges incurred to date	4,700
Furmanite Netherlands and Belgium Exit | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	0	0	(173)
Furmanite Netherlands and Belgium Exit | Disposal (gain) loss & impairment | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 0	$ 0	$ (1,056)