Loans - Wholesale Loan Portfolio, Loan Modifications, Narrative (Details) - Wholesale - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Impaired [Line Items]
New TDRs		$ 801,000,000	$ 881,000,000
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	$ 1,800,000,000
Other
Financing Receivable, Impaired [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	4,000,000
Secured by real estate
Financing Receivable, Impaired [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	$ 0