Revenue Recognition - Remaining Unsatisfied Performance Obligations (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Reaming unsatisfied performance obligation	$ 2,800,422
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue from Contract with Customer [Abstract]
Reaming unsatisfied performance obligation	$ 1,807,078
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining unsatisfied performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-04-01
Revenue from Contract with Customer [Abstract]
Reaming unsatisfied performance obligation	$ 993,344
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining unsatisfied performance obligation, expected timing of satisfaction