Quarterly report pursuant to Section 13 or 15(d)

REVENUES - Operating Revenue (Details)

v3.19.1
REVENUES - Operating Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Disaggregation of Revenue [Line Items]    
Total revenues $ 51,293 $ 57,322
Dry-leasing | United States    
Disaggregation of Revenue [Line Items]    
Total revenues 451 571
Dry-leasing | International    
Disaggregation of Revenue [Line Items]    
Total revenues 3,012 2,001
Operating Income    
Disaggregation of Revenue [Line Items]    
Total revenues 47,830 54,750
Operating Income | United States    
Disaggregation of Revenue [Line Items]    
Total revenues 34,214 39,133
Operating Income | International    
Disaggregation of Revenue [Line Items]    
Total revenues 13,616 15,617
Operating Income | Oil and Gas    
Disaggregation of Revenue [Line Items]    
Total revenues 46,082 52,153
Operating Income | Oil and Gas | United States    
Disaggregation of Revenue [Line Items]    
Total revenues 32,466 36,536
Operating Income | Oil and Gas | International    
Disaggregation of Revenue [Line Items]    
Total revenues 13,616 15,617
Operating Income | Emergency response services    
Disaggregation of Revenue [Line Items]    
Total revenues $ 1,748 $ 2,597