BUSINESS SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment information:
Total revenues	$ 225,310	$ 116,588	$ 596,677	$ 449,665
Technical Services
Segment information:
Total revenues	211,842	109,278	560,602	417,511
Technical Services | Pressure Pumping
Segment information:
Total revenues	96,322	43,133	243,401	163,614
Technical Services | Downhole Tools
Segment information:
Total revenues	61,979	34,331	177,209	148,994
Technical Services | Coiled Tubing
Segment information:
Total revenues	26,733	12,407	61,900	37,619
Technical Services | Nitrogen
Segment information:
Total revenues	8,996	8,281	28,195	23,834
Technical Services | Snubbing
Segment information:
Total revenues	3,748	1,974	10,685	5,371
Technical Services | All other
Segment information:
Total revenues	14,064	9,152	39,212	38,079
Support Services
Segment information:
Total revenues	13,468	7,310	36,075	32,154
Support Services | Rental Tools
Segment information:
Total revenues	8,545	3,752	23,126	19,227
Support Services | All other
Segment information:
Total revenues	$ 4,923	$ 3,558	$ 12,949	$ 12,927