Fair Value Measurements (Assets And Liabilities Recorded At Fair Value On A Nonrecurring Basis) (Details) - Nonrecurring - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities recorded at fair value	$ 0	$ 0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans	34	66
Loans held-for-sale	236
Other real estate	5	9
Total assets at fair value	275	75
Commercial borrower | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans	27	53
Commercial borrower | Level 3 | International
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans	2
Commercial borrower | Real estate construction | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans	2	2
Commercial borrower | Commercial mortgage | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total loans	$ 3	$ 11