Earnings Per Share (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Debt Instrument [Line Items]
Amount authorized under share repurchase program	$ 6,000
Remaining authorized amount under share repurchases	351
Increase in repurchase capacity	$ 78
Secured Revolving Credit Facility due May 2023 | Bank of America, N.A.
Debt Instrument [Line Items]
Maximum first lien leverage ratio	4.25