Bank Deposits - Deposits from Banking Clients Consisting of Interest Bearing and Noninterest Bearing Deposits (Details) - USD ($)		Sep. 30, 2023	Dec. 31, 2022
Interest-bearing deposits:
Deposits swept from brokerage accounts		$ 217,517,000,000	$ 333,754,000,000
Time certificates of deposit		45,418,000,000	6,047,000,000
Checking		15,560,000,000	19,719,000,000
Savings and other		4,672,000,000	6,098,000,000
Total interest-bearing deposits		283,167,000,000	365,618,000,000
Non-interest-bearing deposits		1,241,000,000	1,106,000,000
Total bank deposits	[1]	284,408,000,000	366,724,000,000
Uninsured time CDs and time deposits in excess of FDIC insurance limits		$ 0	$ 0

[1] Certain prior year amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.