Loans - Wholesale Loan Portfolio, Nonaccrual (Details) - Wholesale - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Nonaccrual [Line Items]
With an allowance	$ 1,543	$ 1,144
Without an allowance	746	910
Total nonaccrual loans	2,289	2,054
Secured by real estate
Financing Receivable, Nonaccrual [Line Items]
With an allowance	290	254
Without an allowance	79	72
Total nonaccrual loans	369	326
Commercial and industrial
Financing Receivable, Nonaccrual [Line Items]
With an allowance	699	604
Without an allowance	449	365
Total nonaccrual loans	1,148	969
Other
Financing Receivable, Nonaccrual [Line Items]
With an allowance	554	286
Without an allowance	218	473
Total nonaccrual loans	$ 772	$ 759