Derivative Financial Instruments - Fair Value of Derivatives and Balance Offsetting (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 12,812	$ 20,025
Derivative Liabilities	12,011	19,118
Gross amounts of receivable subject to enforceable master netting agreements	9,671	15,345
Gross amounts of payable subject to enforceable master netting agreements	9,671	15,345
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements	1,914	2,925
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements	1,136	1,291
Derivative asset	1,227	1,755
Derivative liability	1,204	2,482
Less: Gross amounts of financial instrument collateral received not offset	170	265
Less: Gross amounts of financial instrument collateral posted not offset	15	268
Net amount of derivative asset	1,057	1,490
Net amount of derivative liability	$ 1,189	$ 2,214
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets (includes nil and $16 million designated under fair value option at September 30, 2025 and December 31, 2024, respectively)	Other assets (includes nil and $16 million designated under fair value option at September 30, 2025 and December 31, 2024, respectively)
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Interest, taxes and other liabilities (includes $11 million and $16 million designated under fair value option at September 30, 2025 and December 31, 2024, respectively)	Interest, taxes and other liabilities (includes $11 million and $16 million designated under fair value option at September 30, 2025 and December 31, 2024, respectively)
Trading Assets
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements	$ 1,601	$ 2,813
Trading Liabilities
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements	1,135	1,291
Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	51	124
Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	29	9
Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	710	1,097
Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	434	626
Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	2,027	1,220
Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	2,188	1,092
Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6	25
Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	16	5
Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6	0
Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	11	4
Exchange Traded | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	7	2
Exchange Traded | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	6	2
Exchange Traded | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Exchange Traded | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1	0
OTC Cleared | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	60	68
OTC Cleared | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
OTC Cleared | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6	0
OTC Cleared | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	7	0
OTC Cleared | Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	6	0
OTC Cleared | Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	8	0
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	643	1,027
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	428	624
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	5	0
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	72	97
Bilateral OTC | Foreign exchange contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	8,669	16,292
Bilateral OTC | Foreign exchange contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	8,067	16,241
Bilateral OTC | Equity contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	552	576
Bilateral OTC | Equity contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	994	634
Bilateral OTC | Equity contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	698	440
Bilateral OTC | Equity contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	68	189
Bilateral OTC | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	2,027	1,220
Bilateral OTC | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	2,187	1,092
Bilateral OTC | Credit contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	76	246
Bilateral OTC | Credit contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	59	105
Bilateral OTC | Credit contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	19	25
Bilateral OTC | Credit contracts - bilateral OTC(2) | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	77	94
Bilateral OTC | Other Contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	5	5
Bilateral OTC | Other Contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	23	31
Bilateral OTC | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	25
Bilateral OTC | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	9	5
Bilateral OTC | Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Bilateral OTC | Cash Flow Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	3	4
Bilateral OTC | Cash Flow Hedging | Foreign exchange contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	39	99
Bilateral OTC | Cash Flow Hedging | Foreign exchange contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 2	$ 0