Quarterly report pursuant to Section 13 or 15(d)

REVENUE, CONTRACT ASSETS AND LIABILITIES AND OTHER CONTRACT MATTERS - Remaining Performance Obligation by Year (Details)

v3.19.2
REVENUE, CONTRACT ASSETS AND LIABILITIES AND OTHER CONTRACT MATTERS - Remaining Performance Obligation by Year (Details)
$ in Thousands
Jun. 30, 2019
USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation $ 454,522
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01  
Revenue from Contract with Customer [Abstract]  
Remaining performance obligation, period 6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation $ 146,150
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01  
Revenue from Contract with Customer [Abstract]  
Remaining performance obligation, period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation $ 205,651
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01  
Revenue from Contract with Customer [Abstract]  
Remaining performance obligation, period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation $ 96,481
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01  
Revenue from Contract with Customer [Abstract]  
Remaining performance obligation, period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]  
Remaining performance obligation $ 6,240