Segment Information - Additional Information (Details1) $ in Millions	Jun. 30, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2018-07-01
Segment Reporting Information [Line Items]
Revenue, remaining performance obligation, amount	$ 504
Revenue, remaining performance obligation, expected timing of satisfaction, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Segment Reporting Information [Line Items]
Revenue, remaining performance obligation, amount	$ 559
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-04-01
Segment Reporting Information [Line Items]
Revenue, remaining performance obligation, amount	$ 1,100
Revenue, remaining performance obligation, expected timing of satisfaction, period