RESTRUCTURING AND OTHER RELATED CHARGES - Schedule of Restructuring Charges by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 2,916	$ 3,365	$ 1,676
Operating Group Reorganization
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	2,916	0	0
Operating Group Reorganization | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	2,916
Operating Group Reorganization | Employee Severance | IHT
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	459	0	0
Operating Group Reorganization | Employee Severance | MS
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	514	0	0
Operating Group Reorganization | Employee Severance | Quest Integrity
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	381	0	0
Operating Group Reorganization | Employee Severance | Corporate and shared support services
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits), net	$ 1,562	$ 0	$ 0