Trading Assets and Liabilities - Summary (Details) - USD ($) $ in Millions	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	$ 27,731		$ 22,757
Trading liabilities	2,994		2,355
U.S. Treasury
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	4,470		3,791
U.S. Government agency issued or guaranteed
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	0		2
U.S. Government sponsored enterprises
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	463		1,347
Foreign bonds
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	1,422		914
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	19,354		15,141
Precious metals
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	1,100		196
Trading liabilities	640		86
Precious metals \| Reclassification
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	800	$ 1,200
Trading liabilities	500	$ 800
Securities sold, not yet purchased
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities	746		1,438
Derivatives, net
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	922		1,366
Trading liabilities	$ 1,608		$ 831