Exit and Other Related Liabilities - Summary of Exit and Other Related Costs Recognized in Expense (Details) - USD ($) $ in Millions	12 Months Ended			39 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2023
TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	$ 60	$ 34	$ 108	$ 388
Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	495
Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	24	25	83	308
Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	292
Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	11	9	22	49
Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	17
Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				3
Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			1	1
Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	5
Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	25		2	27
Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	181
Investor Services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	47	26	87	306
Investor Services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	365
Investor Services | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	20	19	66	243
Investor Services | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	214
Investor Services | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	9	7	18	40
Investor Services | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	13
Investor Services | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				2
Investor Services | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			1	1
Investor Services | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4
Investor Services | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	18		2	20
Investor Services | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	134
Investor Services | Employee Severance And Retention | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	20	19	66	243
Investor Services | Employee Severance And Retention | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	20	19	66	243
Investor Services | Employee Severance And Retention | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0	0	0	0
Investor Services | Employee Severance And Retention | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				0
Investor Services | Employee Severance And Retention | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			0	0
Investor Services | Employee Severance And Retention | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0		0	0
Investor Services | Employee Compensation and Benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	214
Investor Services | Employee Compensation and Benefits | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	214
Investor Services | Employee Compensation and Benefits | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Investor Services | Employee Compensation and Benefits | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Investor Services | Employee Compensation and Benefits | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Investor Services | Facility Exit Costs | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	27	7	21	63
Investor Services | Facility Exit Costs | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	151
Investor Services | Facility Exit Costs | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0	0	0	0
Investor Services | Facility Exit Costs | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Investor Services | Facility Exit Costs | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	9	7	18	40
Investor Services | Facility Exit Costs | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	13
Investor Services | Facility Exit Costs | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				2
Investor Services | Facility Exit Costs | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			1	1
Investor Services | Facility Exit Costs | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4
Investor Services | Facility Exit Costs | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	18		2	20
Investor Services | Facility Exit Costs | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	134
Advisor Services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	13	8	21	82
Advisor Services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	130
Advisor Services | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4	6	17	65
Advisor Services | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	78
Advisor Services | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	2	2	4	9
Advisor Services | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4
Advisor Services | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				1
Advisor Services | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			0	0
Advisor Services | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	1
Advisor Services | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	7		0	7
Advisor Services | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	47
Advisor Services | Employee Severance And Retention | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4	6	17	65
Advisor Services | Employee Severance And Retention | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4	6	17	65
Advisor Services | Employee Severance And Retention | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0	0	0	0
Advisor Services | Employee Severance And Retention | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				0
Advisor Services | Employee Severance And Retention | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			0	0
Advisor Services | Employee Severance And Retention | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0		0	0
Advisor Services | Employee Compensation and Benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	78
Advisor Services | Employee Compensation and Benefits | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	78
Advisor Services | Employee Compensation and Benefits | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Advisor Services | Employee Compensation and Benefits | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Advisor Services | Employee Compensation and Benefits | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Advisor Services | Facility Exit Costs | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	9	2	4	17
Advisor Services | Facility Exit Costs | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	52
Advisor Services | Facility Exit Costs | Compensation and benefits | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0	0	0	0
Advisor Services | Facility Exit Costs | Compensation and benefits | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	0
Advisor Services | Facility Exit Costs | Occupancy and equipment | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	2	$ 2	4	9
Advisor Services | Facility Exit Costs | Occupancy and equipment | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	4
Advisor Services | Facility Exit Costs | Depreciation and amortization | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense				1
Advisor Services | Facility Exit Costs | Professional services | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense			0	0
Advisor Services | Facility Exit Costs | Professional services | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	1
Advisor Services | Facility Exit Costs | Other | TD Ameritrade Integration
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	7		$ 0	$ 7
Advisor Services | Facility Exit Costs | Other | Other Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Amounts recognized in expense	$ 47