Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill		$ 733
Goodwill	$ 3,451	3,385
Goodwill and Intangible Asset Impairment	26	11	$ 9
Amortization of Intangible Assets	173	$ 165	129
Amortization expense of intangible assets next 12 months	188
Finite-Lived Intangible Assets, Amortization Expense, Year Two	178
Finite-Lived Intangible Assets, Amortization Expense, Year Three	164
Finite-Lived Intangible Assets, Amortization Expense, Year Four	153
Finite-Lived Intangible Assets, Amortization Expense, Year Five	132
Series of Individually Immaterial Business Acquisitions [Member]
Goodwill
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill			132
Goodwill	$ 2		$ 187