Revenue Recognition Remaining Performance Obligations (Details) $ in Millions	Dec. 31, 2020 USD ($)
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	$ 837
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue expected to be recognized	837
Corporate and Other [Member]
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	837
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue expected to be recognized	837
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	$ 267
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected timing of satisfaction, period	1 year
Revenue expected to be recognized	$ 267
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Corporate and Other [Member]
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	267
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue expected to be recognized	267
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	$ 570
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Expected timing of satisfaction, period
Revenue expected to be recognized	$ 570
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Corporate and Other [Member]
Revenue from Contract with Customer [Abstract]
Revenue expected to be recognized	570
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue expected to be recognized	$ 570