SEGMENT AND GEOGRAPHIC DISCLOSURES - Segment Data for our Three Operating Segments (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues		$ 287,807	$ 290,079	$ 315,829	$ 269,599	$ 309,799	$ 290,856	$ 343,889	$ 302,385	$ 1,163,314	$ 1,246,929	$ 1,200,211
Operating income (loss)		$ 3,218	$ (1,840)	$ 13,004	$ (16,528)	$ (6,941)	$ (19,694)	$ 1,799	$ (14,125)	(2,146)	(38,961)	(115,110)
Capital expenditures	[1]									31,734	25,931	36,798
Depreciation and amortization										49,059	64,862	52,143
IHT
Segment Reporting Information [Line Items]
Revenues										512,950	617,378
MS
Segment Reporting Information [Line Items]
Revenues										535,372	532,365
Quest Integrity
Segment Reporting Information [Line Items]
Revenues										114,992	97,186
Operating Segments | IHT
Segment Reporting Information [Line Items]
Revenues										512,950	617,378	588,441
Operating income (loss)	[2]									24,084	37,329	11,128
Capital expenditures	[1]									7,983	7,643	10,505
Depreciation and amortization										17,616	18,810	19,279
Operating Segments | MS
Segment Reporting Information [Line Items]
Revenues										535,372	532,365	529,973
Operating income (loss)	[2]									55,385	6,323	(33,993)
Capital expenditures	[1]									10,755	11,141	17,791
Depreciation and amortization										21,835	36,177	23,412
Operating Segments | Quest Integrity
Segment Reporting Information [Line Items]
Revenues										114,992	97,186	81,797
Operating income (loss)										28,757	20,138	12,337
Capital expenditures	[1]									4,550	3,526	3,316
Depreciation and amortization										3,557	4,285	4,423
Corporate and shared support services
Segment Reporting Information [Line Items]
Operating income (loss)										(110,372)	(102,751)	(104,582)
Capital expenditures	[1]									8,446	3,621	5,186
Depreciation and amortization										$ 6,051	$ 5,590	$ 5,029

[1] Excludes finance leases. Totals may vary from amounts presented in the consolidated statements of cash flows due to the timing of cash payments.

[2] Includes goodwill impairment loss of $21.1 million and $54.1 million for IHT and MS, respectively, for the year ended December 31, 2017.