Annual report pursuant to Section 13 and 15(d)

Revenue (Obligation) (Details)

v3.10.0.1
Revenue (Obligation) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
USD ($)
Revenue from Contract with Customer [Abstract]  
Total $ 515,453
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 195,913
Remaining Performance Obligations  
Revenue recognition period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 127,516
Remaining Performance Obligations  
Revenue recognition period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 76,828
Remaining Performance Obligations  
Revenue recognition period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 56,378
Remaining Performance Obligations  
Revenue recognition period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 22,496
Remaining Performance Obligations  
Revenue recognition period 1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01  
Revenue from Contract with Customer [Abstract]  
Total $ 36,322
Remaining Performance Obligations  
Revenue recognition period