Revenue Recognition (Remaining Performance Obligations) (Details) $ in Billions	Dec. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Transaction price allocated to remaining performance obligations	$ 19
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligation	50.00%
Estimated timing of recognition of performance obligation	5 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percentage of remaining performance obligation	50.00%
Estimated timing of recognition of performance obligation