Quarterly report pursuant to Section 13 or 15(d)

REVENUE - Transaction price allocated to the remaining performance obligations (Details)

v3.10.0.1
REVENUE - Transaction price allocated to the remaining performance obligations (Details) - Fixed-price contracts
$ in Thousands
6 Months Ended
Jun. 30, 2018
USD ($)
Transaction price allocated to the remaining performance obligations  
Remaining performance obligation $ 25,644
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01  
Transaction price allocated to the remaining performance obligations  
Remaining performance obligation $ 6,500
Expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01  
Transaction price allocated to the remaining performance obligations  
Remaining performance obligation $ 6,500
Expected timing of satisfaction 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01  
Transaction price allocated to the remaining performance obligations  
Remaining performance obligation $ 12,644
Expected timing of satisfaction