BUSINESS SEGMENT INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment information:
Total revenues	$ 89,300	$ 358,516	$ 333,077	$ 693,172
Technical Services
Segment information:
Total revenues	80,532	338,034	308,232	652,113
Technical Services | Pressure Pumping
Segment information:
Total revenues	23,717	170,066	120,481	317,825
Technical Services | Downhole Tools
Segment information:
Total revenues	35,151	112,763	121,059	222,434
Technical Services | Coiled Tubing
Segment information:
Total revenues	8,973	21,284	25,212	41,462
Technical Services | Nitrogen
Segment information:
Total revenues	5,621	12,219	15,553	23,527
Technical Services | Snubbing
Segment information:
Total revenues	1,093	4,355	3,397	7,818
Technical Services | All other
Segment information:
Total revenues	5,977	17,347	22,530	39,047
Support Services
Segment information:
Total revenues	8,768	20,482	24,845	41,059
Support Services | Rental Tools
Segment information:
Total revenues	5,069	13,962	15,475	27,898
Support Services | All other
Segment information:
Total revenues	$ 3,699	$ 6,520	$ 9,370	$ 13,161