BUSINESS SEGMENT INFORMATION - Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Revenues	$ 182,610	$ 243,777
Operating (loss) income:
Operating loss	(10,521)	(218,707)
Capital expenditures	11,750	25,019
Depreciation and amortization	17,773	39,293
Identifiable assets	800,073	897,630
Impairment and other charges	0	205,536
Gain on disposition of assets, net	1,460	819
Interest expense	380	113
Interest income	18	334
Other (expense) income , net	507	(308)
Loss before income taxes	(10,376)	(218,794)
Technical Services
Revenues:
Revenues	172,641	227,700
Operating (loss) income:
Operating loss	(5,762)	(12,207)
Capital expenditures	9,648	20,338
Depreciation and amortization	15,728	36,995
Identifiable assets	507,815	654,354
Support Services
Revenues:
Revenues	9,969	16,077
Operating (loss) income:
Operating loss	(2,896)	1,547
Capital expenditures	1,937	4,681
Depreciation and amortization	1,977	2,228
Identifiable assets	70,304	70,022
Corporate
Operating (loss) income:
Operating loss	(3,323)	(3,330)
Capital expenditures	165
Depreciation and amortization	68	70
Identifiable assets	$ 221,954	$ 173,254