Revenue (Performance Obligation) (Details) $ in Billions	Dec. 31, 2019 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation	$ 11.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected to be satisfied, percentage	34.00%
Revenue, remaining performance obligation, expected timing of satisfaction (year)	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected to be satisfied, percentage	33.00%
Revenue, remaining performance obligation, expected timing of satisfaction (year)	4 years