Derivative Financial Instruments - Fair Value of Derivatives and Balance Offsetting (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 17,169	$ 19,944
Derivative Liabilities	17,263	19,320
Gross amounts of receivable subject to enforceable master netting agreements	14,110	15,625
Gross amounts of payable subject to enforceable master netting agreements	14,110	15,625
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements	1,760	2,653
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements	1,321	1,529
Derivative asset	1,299	1,666
Derivative liability	1,832	2,166
Less: Gross amounts of financial instrument collateral received not offset	63	234
Less: Gross amounts of financial instrument collateral posted not offset	273	32
Net amount of derivative asset	1,236	1,432
Net amount of derivative liability	$ 1,559	$ 2,134
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Interest, taxes and other liabilities (includes $10 million and $325 million designated under fair value option at December 31, 2023 and 2022, respectively)	Interest, taxes and other liabilities (includes $10 million and $325 million designated under fair value option at December 31, 2023 and 2022, respectively)
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets, net of allowance for credit losses of nil at both December 31, 2023 and 2022 (includes $10 million and $325 million designated under fair value option at December 31, 2023 and 2022, respectively)	Other assets, net of allowance for credit losses of nil at both December 31, 2023 and 2022 (includes $10 million and $325 million designated under fair value option at December 31, 2023 and 2022, respectively)
Trading Assets
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral received subject to enforceable master netting agreements	$ 1,416	$ 2,653
Trading Liabilities
Derivatives, Fair Value [Line Items]
Less: Gross amounts of cash collateral posted subject to enforceable master netting agreements	1,321	1,180
Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	42
Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	140	86
Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1,255	1,814
Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	962	1,371
Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	420	630
Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1,080	270
Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1,153	1,201
Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1,033	1,255
Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	95	103
Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	137	45
Credit contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	14	7
Credit contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	123	61
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1,178	1,764
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	946	1,364
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Bilateral OTC | Interest rate contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	76	97
Bilateral OTC | Foreign exchange contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	13,606	15,744
Bilateral OTC | Foreign exchange contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	13,479	15,440
Bilateral OTC | Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	413	630
Bilateral OTC | Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1,080	266
Bilateral OTC | Equity contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	621	398
Bilateral OTC | Equity contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	193	657
Bilateral OTC | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1,150	1,201
Bilateral OTC | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1,033	1,254
Bilateral OTC | Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	81	103
Bilateral OTC | Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	137	45
Bilateral OTC | Credit contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	13	7
Bilateral OTC | Credit contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	122	60
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	40	38
Bilateral OTC | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	42
Bilateral OTC | Fair Value Hedging | Interest rate contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	83	12
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	1	4
Bilateral OTC | Cash Flow Hedging | Foreign exchange contracts | Designated as Hedging Instrument | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Bilateral OTC | Cash Flow Hedging | Foreign exchange contracts | Designated as Hedging Instrument | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	56	70
OTC Cleared | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	70	42
OTC Cleared | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
OTC Cleared | Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	14	0
OTC Cleared | Credit contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	0
OTC Cleared | Credit contracts | Not Designated as Hedging Instrument, Other | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets	1	0
OTC Cleared | Credit contracts | Not Designated as Hedging Instrument, Other | Interest taxes and other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	1	1
Exchange Traded | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	7	8
Exchange Traded | Interest rate contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	16	7
Exchange Traded | Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	7	0
Exchange Traded | Equity contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	0	4
Exchange Traded | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Assets
Derivatives, Fair Value [Line Items]
Derivative Assets	3	0
Exchange Traded | Precious metals contracts | Not Designated as Hedging Instrument, Trading | Trading Liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 0	$ 1