Business Acquisitions (Pro Forma Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
TD Ameritrade [Member]
Business Acquisition [Line Items]
Total net revenues	$ 16,514	$ 16,561
Net income	4,655	5,240
USAA-IMCO [Member]
Business Acquisition [Line Items]
Total net revenues	11,794	11,057
Net income	$ 3,005	$ 3,407