Summary of Significant Accounting and Reporting Policies - Accounting Standards (Details) - USD ($) $ in Millions	Jan. 01, 2023	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for loan and lease losses		$ (2,194)	[1]	$ (1,892)	[1]	$ (2,453)	$ (1,202)
Retained earnings		$ 21,689		$ 20,236
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for loan and lease losses							$ (643)
Cumulative Effect, Period of Adoption, Adjustment | Accounting Standards Update 2022-02 | Subsequent Event
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for loan and lease losses	$ 49
Retained earnings	$ 37

[1] Includes $17 and $24 of other short-term investments, $185 and $322 of portfolio loans and leases, $(2) and $(2) of ALLL, $2 and $2 of other assets, $9 and $1 of other liabilities and $118 and $263 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2022 and 2021, respectively. For further information, refer to Note 12.