Segment Information - Additional Information (Details1) $ in Millions	Dec. 31, 2018 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-01-01
Segment Reporting Information [Line Items]
Revenue, remaining performance obligation, amount	$ 176
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-04-01
Segment Reporting Information [Line Items]
Revenue, remaining performance obligation, amount	$ 636
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	$ 1,400
Revenue, remaining performance obligation, expected timing of satisfaction, period