BUSINESS SEGMENT INFORMATION - Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Revenues	$ 89,300	$ 358,516	$ 333,077	$ 693,172
Operating (loss) income:
Operating (loss) income	(37,530)	8,387	(256,237)	6,226
Capital expenditures			38,659	132,253
Depreciation and amortization	19,573	42,881	58,866	85,386
Identifiable assets	782,868	1,223,967	782,868	1,223,967
Impairment and other charges	(1,639)	0	(207,175)	0
Gain on disposition of assets, net	3,194	1,133	4,013	4,637
Interest expense	71	164	184	253
Interest income	68	594	402	1,394
Other (expense) income , net	(1,481)	(53)	(1,789)	392
(Loss) income before income taxes	(39,014)	8,764	(257,808)	7,759
Technical Services
Revenues:
Revenues	80,532	338,034	308,232	652,113
Operating (loss) income:
Operating (loss) income	(34,100)	6,850	(46,307)	2,392
Capital expenditures			31,296	125,171
Depreciation and amortization			54,615	80,370
Identifiable assets	474,670	1,030,073	474,670	1,030,073
Support Services
Revenues:
Revenues	8,768	20,482	24,845	41,059
Operating (loss) income:
Operating (loss) income	(1,846)	4,018	(299)	7,155
Capital expenditures			7,027	6,260
Depreciation and amortization			4,111	4,856
Identifiable assets	62,867	86,928	62,867	86,928
Corporate
Operating (loss) income:
Operating (loss) income	(3,139)	(3,614)	(6,469)	(7,958)
Capital expenditures			336	822
Depreciation and amortization			140	160
Identifiable assets	$ 245,331	$ 106,966	245,331	$ 106,966
Impairment and other charges			$ 541