Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Cash and cash equivalents		$ 459	$ 294	$ 1,419	$ 461
Cash and investments segregated		285	214	1,041	308
Receivables from brokerage clients		1,282	912	3,533	2,244
Available for sale securities		724	1,161	2,340	3,196
Held to maturity securities		706	345	2,172	1,062
Bank loans		426	300	1,227	717
Securities lending revenue		105	124	341	383
Other interest revenue		41	7	75	15
Interest revenue		4,028	3,357	12,148	8,386
Bank deposits		(911)	(241)	(2,392)	(285)
Payables to brokerage clients		(66)	(41)	(205)	(47)
Other short-term borrowings		(97)	(4)	(280)	(12)
Federal Home Loan Bank borrowings		(477)	0	(1,387)	0
Long-term debt		(193)	(131)	(489)	(363)
Securities lending expense		(46)	(13)	(96)	(28)
Other interest expense		(1)	(1)	(2)	2
Interest expense		(1,791)	(431)	(4,851)	(733)
Net interest revenue		2,237	2,926	7,297	7,653
Total net revenues		4,606	5,500	14,378	15,265
Asset management and administration fees
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	[1]	1,224	1,047	3,515	3,167
Mutual funds, ETFs, and CTFs
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		666	520	1,881	1,524
Advice solutions
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		476	452	1,393	1,409
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		82	75	241	234
Trading revenue
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		768	930	2,463	2,778
Commissions
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		394	435	1,210	1,362
Order flow revenue
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		325	432	1,104	1,332
Principal transactions
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		49	63	149	84
Bank deposit account fees
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		205	413	531	1,059
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers		$ 172	$ 184	$ 572	$ 608

[1] No fee waivers were recognized for the three and nine months ended September 30, 2023, or for the three months ended September 30, 2022. Includes fee waivers of $57 million for the nine months ended September 30, 2022.