Exit and Other Related Liabilities - Activity in Exit and Other Related Liabilities (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		36 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023
TD Ameritrade Integration
Restructuring Reserve [Roll Forward]
Balance at beginning of period			$ 46
Amounts recognized in expense	$ 16	$ 9	56	$ 29	$ 384
Costs paid or otherwise settled			(12)
Balance at end of period	57		57		57
TD Ameritrade Integration | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	9	6	23	23	307
Other
Restructuring Reserve [Roll Forward]
Balance at beginning of period			0
Amounts recognized in expense	279		279
Costs paid or otherwise settled			0
Balance at end of period	276		276		276
Other | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	276		276
Investor Services Employee Compensation and Benefits | TD Ameritrade Integration
Restructuring Reserve [Roll Forward]
Balance at beginning of period			36
Amounts recognized in expense	16	7	44	22	303
Costs paid or otherwise settled			(10)
Balance at end of period	46		46		46
Investor Services Employee Compensation and Benefits | TD Ameritrade Integration | Employee Severance And Retention
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	9	5	20	18	243
Investor Services Employee Compensation and Benefits | TD Ameritrade Integration | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	9	5	20	18	243
Investor Services Employee Compensation and Benefits | TD Ameritrade Integration | Compensation and benefits | Employee Severance And Retention
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	9	5	20	18	243
Investor Services Employee Compensation and Benefits | Other
Restructuring Reserve [Roll Forward]
Balance at beginning of period			0
Amounts recognized in expense	204		204
Costs paid or otherwise settled			0
Balance at end of period	202		202		202
Investor Services Employee Compensation and Benefits | Other | Employee Compensation and Benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	202		202
Investor Services Employee Compensation and Benefits | Other | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	202		202
Investor Services Employee Compensation and Benefits | Other | Compensation and benefits | Employee Compensation and Benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	202		202
Advisor Services Employee Compensation and Benefits | TD Ameritrade Integration
Restructuring Reserve [Roll Forward]
Balance at beginning of period			10
Amounts recognized in expense	0	2	12	7	81
Costs paid or otherwise settled			(2)
Balance at end of period	11		11		11
Advisor Services Employee Compensation and Benefits | TD Ameritrade Integration | Employee Severance And Retention
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	0	1	3	5	64
Advisor Services Employee Compensation and Benefits | TD Ameritrade Integration | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	0	1	3	5	64
Advisor Services Employee Compensation and Benefits | TD Ameritrade Integration | Compensation and benefits | Employee Severance And Retention
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	0	$ 1	3	$ 5	64
Advisor Services Employee Compensation and Benefits | Other
Restructuring Reserve [Roll Forward]
Balance at beginning of period			0
Amounts recognized in expense	75		75
Costs paid or otherwise settled			0
Balance at end of period	74		74		$ 74
Advisor Services Employee Compensation and Benefits | Other | Employee Compensation and Benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	74		74
Advisor Services Employee Compensation and Benefits | Other | Compensation and benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	74		74
Advisor Services Employee Compensation and Benefits | Other | Compensation and benefits | Employee Compensation and Benefits
Restructuring Reserve [Roll Forward]
Amounts recognized in expense	$ 74		$ 74