Accounting Policies (Details) $ in Millions	9 Months Ended
	Sep. 30, 2023 USD ($) country	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of countries outside the US where strategic international offices are held | country	4
Allowance for loan and lease losses	$ (4,767)	$ (4,737)	$ (4,741)	$ (4,581)	$ (4,462)	$ (4,868)
Retained earnings	$ 56,170		53,572
Cumulative Effect, Period of Adoption, Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Allowance for loan and lease losses			35
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Allowance for loan and lease losses			35
Retained earnings			$ 26