Loans - Wholesale Loan Portfolio, Nonaccrual Loans (Details) - Wholesale - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Nonaccrual [Line Items]
With an allowance	$ 2,774	$ 2,283
Without an allowance	1,966	1,659
Total nonaccrual loans	4,740	3,942
Secured by real estate
Financing Receivable, Nonaccrual [Line Items]
With an allowance	515	366
Without an allowance	1,020	1,073
Total nonaccrual loans	1,535	1,439
Commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
With an allowance	1,880	1,362
Without an allowance	525	398
Total nonaccrual loans	2,405	1,760
Other
Financing Receivable, Nonaccrual [Line Items]
With an allowance	379	555
Without an allowance	421	188
Total nonaccrual loans	$ 800	$ 743