Exit and Other Related Liabilities - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended		36 Months Ended
	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) clientTransitionGroup	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)
TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Acquisition-related exit costs	$ 16	$ 9	$ 56	$ 29	$ 384
Other
Restructuring Cost and Reserve [Line Items]
Acquisition-related exit costs	279		279
Minimum | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Expected integration exit and other related costs	500		500		500
Minimum | Other
Restructuring Cost and Reserve [Line Items]
Expected integration exit and other related costs	400		400		400
Maximum | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Expected integration exit and other related costs	700		$ 700		700
Expected period of remaining costs to be incurred			15 months
Maximum | Other
Restructuring Cost and Reserve [Line Items]
Expected integration exit and other related costs	$ 500		$ 500		$ 500
TD Ameritrade, Inc.
Restructuring Cost and Reserve [Line Items]
Number of integration client transition groups | clientTransitionGroup			3