Loans - Wholesale Loan Portfolio, Nonaccrual Loans (Details) - Wholesale - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Financing Receivable, Nonaccrual [Line Items]
With an allowance	$ 2,644	$ 2,395
Without an allowance	1,880	2,003
Total nonaccrual loans	4,524	4,398
Secured by real estate
Financing Receivable, Nonaccrual [Line Items]
With an allowance	447	365
Without an allowance	1,296	1,313
Total nonaccrual loans	1,743	1,678
Commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
With an allowance	1,800	1,562
Without an allowance	357	392
Total nonaccrual loans	2,157	1,954
Other
Financing Receivable, Nonaccrual [Line Items]
With an allowance	397	468
Without an allowance	227	298
Total nonaccrual loans	$ 624	$ 766