Business Acquisitions (USAA-IMCO Narrative) (Details) account in Millions, $ in Millions		3 Months Ended	7 Months Ended		12 Months Ended
	May 26, 2020 USD ($) account	Sep. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)		Dec. 31, 2020 USD ($)		Dec. 31, 2019 USD ($)		Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill			$ 11,952	[1]	$ 11,952	[1]	$ 1,227	[1]	$ 1,227
USAA-IMCO [Member]
Business Acquisition [Line Items]
Purchase price	$ 1,581
Number of brokerage and managed portfolio accounts acquired | account	1
Client assets acquired	$ 80,000
Adjustment to intangible assets		$ 9
Adjustment to purchase price		43
Adjustment to goodwill		$ 34
Intangible assets acquired	1,109
Goodwill	$ 472
Net revenue			235
Net loss			$ 51
Post-closing adjustment					21
Acquisition costs					54		14
After-tax acquisition and integration-related costs					$ 41		$ 10

[1] Certain prior year amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.