Fair Value (Schedule of Assets and Liabilities Measured at Fair Value by Class on a Recurring Basis Using Level 3 Inputs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Securities gains (losses), net	Securities gains (losses), net
Debt And Equity Securities, Unrealized Gain (Loss)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Securities gains (losses), net	Securities gains (losses), net
Other Noninterest Expense
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other	Other
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized securitites gains (losses), net and Other noninterest income (expense)	$ (2)	$ 31
Level 3 | Private equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of year	66	80
Purchases	16	17
Cost of investments sold	(3)	(24)
Redemptions and paydowns	0	0
Transfers out	(1)	(78)
Balance at end of year	81	66
Level 3 | Private equity investments | Debt And Equity Securities, Unrealized Gain (Loss)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized securitites gains (losses), net and Other noninterest income (expense)	3	71
Level 3 | Private equity investments | Other Noninterest Expense
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized securitites gains (losses), net and Other noninterest income (expense)	0	0
Level 3 | Ag loan servicing & interest-only strips
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of year	12	16
Purchases	0	0
Cost of investments sold	0	0
Redemptions and paydowns	0	(1)
Transfers out	0	0
Balance at end of year	14	12
Level 3 | Ag loan servicing & interest-only strips | Debt And Equity Securities, Unrealized Gain (Loss)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized securitites gains (losses), net and Other noninterest income (expense)	0	0
Level 3 | Ag loan servicing & interest-only strips | Other Noninterest Expense
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Unrealized securitites gains (losses), net and Other noninterest income (expense)	$ 2	$ (3)