Loans and Related Allowance for Credit Losses (Nonperforming Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing receivable, nonaccrual, no allowance	$ 600	$ 500
Nonperforming
Total nonperforming loans	2,326	2,180
OREO and Foreclosed Assets	31	36
Total nonperforming assets	$ 2,357	$ 2,216
Nonperforming loans to total loans	0.73%	0.68%
Nonperforming assets to total loans, OREO and foreclosed assets	0.74%	0.69%
Nonperforming assets to total assets	0.42%	0.39%
Minimum
Threshold period of financing receivable past due, writeoff	120 days
Maximum
Threshold period of financing receivable past due, writeoff	180 days
Commercial | Nonperforming
Total nonperforming loans	$ 1,462	$ 1,307
Consumer | Nonperforming
Total nonperforming loans	$ 864	$ 873