Quarterly report pursuant to Section 13 or 15(d)

Revenues - Performance Obligations and Contract Balances (Details)

v3.19.2
Revenues - Performance Obligations and Contract Balances (Details) - USD ($)
Jun. 30, 2019
Dec. 31, 2018
Revenue from Contract with Customer [Abstract]    
Contract assets $ 0 $ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]    
Remaining performance obligation $ 114,800,000  
Revenue recognition period P2Y5M