SEGMENT AND GEOGRAPHIC DISCLOSURES - Segment Data for our Three Operating Segments (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Segment Reporting Information [Line Items]
Revenues		$ 247,780	$ 217,410	$ 717,621	$ 650,901
Depreciation and amortization	[1]			28,591	31,416
Continuing Operations
Segment Reporting Information [Line Items]
Revenues		218,339	197,879	628,917	591,043
Operating income (loss)		(1,729)	(72,228)	(34,929)	(107,972)
Capital expenditures		4,258	2,488	14,846	10,599
Depreciation and amortization		8,987	9,516	27,449	29,400
IHT | Continuing Operations
Segment Reporting Information [Line Items]
Revenues		110,312	101,476	320,033	310,077
MS | Continuing Operations
Segment Reporting Information [Line Items]
Revenues		108,027	96,403	308,884	280,966
Operating segments | IHT | Continuing Operations
Segment Reporting Information [Line Items]
Revenues		110,312	101,476	320,033	310,077
Operating income (loss)		7,390	3,065	13,038	10,824
Capital expenditures		2,557	1,454	10,654	6,625
Depreciation and amortization		3,022	3,148	9,372	9,888
Operating segments | MS | Continuing Operations
Segment Reporting Information [Line Items]
Revenues		108,027	96,403	308,884	280,966
Operating income (loss)		7,655	(53,242)	15,152	(50,799)
Capital expenditures		1,427	741	3,861	3,260
Depreciation and amortization		4,704	4,950	14,222	15,432
Corporate and shared support services | Continuing Operations
Segment Reporting Information [Line Items]
Operating income (loss)		(16,774)	(22,051)	(63,119)	(67,997)
Capital expenditures		274	293	331	714
Depreciation and amortization		$ 1,261	$ 1,418	$ 3,855	$ 4,080

[1] Condensed consolidated statements of cash flows include discontinued operations. September 30, 2022September 30, 2021Cash and cash equivalents from continuing operations$56,387 $12,009 Cash and cash equivalents from discontinued operations10,641 4,963 Total$67,028 $16,972