Quarterly report pursuant to Section 13 or 15(d)

REVENUE - Disaggregation of revenue (Details)

v3.19.1
REVENUE - Disaggregation of revenue (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Disaggregation of revenue    
Revenue $ 50,652 $ 43,121
Canada    
Disaggregation of revenue    
Revenue 1,449  
U.S.    
Disaggregation of revenue    
Revenue 49,204 43,121
Cost-plus reimbursement contracts    
Disaggregation of revenue    
Revenue 43,503 33,777
Fixed-price contracts    
Disaggregation of revenue    
Revenue $ 7,149 $ 9,344