Revenue - Remaining Performance Obligation (Details) $ in Millions	Jun. 30, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Performance obligation, amount	$ 113
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01
Revenue from Contract with Customer [Abstract]
Performance obligation, amount	$ 52
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Revenue from Contract with Customer [Abstract]
Performance obligation, amount	$ 61
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Performance period