Trading Assets and Liabilities - Summary (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
		Sep. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Debt and Equity Securities, FV-NI [Line Items]
Trading assets	[1]		$ 22,115	$ 21,730
Trading liabilities	[1]		3,485	2,803
Proceeds from sale of trading assets			10	0	$ 0
Affiliated Entity
Debt and Equity Securities, FV-NI [Line Items]
Proceeds from sale of trading assets		$ 900
U.S. Treasury
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			3,564	1,670
U.S. Government agency issued or guaranteed
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			1	0
U.S. Government sponsored enterprises
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			1,207	369
Foreign bonds
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			4,019	6,391
Equity securities
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			11,702	7,855
Precious metals(1)
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			346	3,831
Trading liabilities			301	0
Securities sold, not yet purchased
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities			1,688	837
Derivative assets
Debt and Equity Securities, FV-NI [Line Items]
Trading assets			1,276	1,614
Derivatives liability
Debt and Equity Securities, FV-NI [Line Items]
Trading liabilities			$ 1,496	$ 1,966

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2023 and 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20232022(in millions)AssetsLoans, net$— $162 Other assets23 44 Total assets$23 $206 LiabilitiesInterest, taxes and other liabilities$17 $22 Total liabilities$17 $22