Basis of Presentation - Performance Obligation Expected Satisfaction (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amount	$ 89,684
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amount	$ 15,232
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Expected Timing	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amount	$ 36,817
Expected Timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Amount	$ 37,635
Expected Timing	1 year