Significant Group Concentrations of Credit Risk Significant Group Concentrations of Credit Risk (Schedule of Automotive Industry Outstanding Loans and Total Exposure) (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Concentration Risk [Line Items]
Total automotive loans	$ 7,039	$ 6,435
Total automotive exposure	$ 12,162	12,938
Concentration risk threshold - Commercial Real Estate	36.00%
Automotive Production
Concentration Risk [Line Items]
Total automotive exposure	$ 1,744	2,028
Automotive Dealer
Concentration Risk [Line Items]
Total automotive loans	6,191	5,367
Total automotive exposure	$ 10,418	$ 10,910