Collateralized Agreements and Offsetting Arrangements - Remaining Contractual Maturity (Details) - Asset Pledged as Collateral - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	$ 10,677	$ 9,559
U.S Treasury securities and other \| Securities sold under agreements to repurchase
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	5,461	8,220
U.S Treasury securities and other \| Overnight and continuous \| Securities sold under agreements to repurchase
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	4,714	0
U.S Treasury securities and other \| 30 days or less \| Securities sold under agreements to repurchase
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	0	8,220
U.S Treasury securities and other \| After 30 days through 90 days \| Securities sold under agreements to repurchase
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	747	0
U.S Treasury securities and other \| Greater than 90 days \| Securities sold under agreements to repurchase
Collateral in the Form of Securities Pledged [Line Items]
Financial Instruments, Owned, at Fair Value	$ 0	$ 0