BUSINESS SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment information:
Total revenues	$ 116,588	$ 293,240	$ 449,665	$ 986,412
Technical Services
Segment information:
Total revenues	109,278	274,483	417,511	926,596
Technical Services | Pressure Pumping
Segment information:
Total revenues	43,133	111,163	163,614	428,988
Technical Services | Downhole Tools
Segment information:
Total revenues	34,331	111,619	148,994	334,053
Technical Services | Coiled Tubing
Segment information:
Total revenues	12,407	19,622	37,619	61,084
Technical Services | Nitrogen
Segment information:
Total revenues	8,281	10,140	23,834	33,667
Technical Services | Snubbing
Segment information:
Total revenues	1,974	4,407	5,371	12,225
Technical Services | All other
Segment information:
Total revenues	9,152	17,532	38,079	56,579
Support Services
Segment information:
Total revenues	7,310	18,757	32,154	59,816
Support Services | Rental Tools
Segment information:
Total revenues	3,752	12,479	19,227	40,377
Support Services | All other
Segment information:
Total revenues	$ 3,558	$ 6,278	$ 12,927	$ 19,439