Financial Instruments Subject to Off-Balance Sheet Credit Risk (Summary of the Fair Value of Client Securities Available to Utilize as Collateral and Amounts Pledged) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Securities Financing Transaction [Line Items]
Fair value of client securities available to be pledged	$ 98,176	$ 120,306
Total collateral pledged to third parties	25,339	31,422
Fulfillment of Requirements with the Options Clearing Corporation [Member]
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	16,427	16,829
Fulfillment of Client Short Sales [Member]
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	4,606	5,934
Securities Lending to Other Broker-Dealers [Member]
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	4,306	6,269
Collateral For Short-Term Borrowings [Member]
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	0	2,390
Fully Paid Client Securities [Member]
Securities Financing Transaction [Line Items]
Total collateral pledged to third parties	$ 192	$ 118