Acquisitions and Dispositions (Acquired Finite-Lived Intangibles Assets) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 278
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 255
Weighted Average Amortization Period	13 years 8 months 12 days
Other
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 23
Weighted Average Amortization Period	4 years 3 months 18 days