Loans - Wholesale Loan Portfolio, Loan Modifications, Narrative (Details) - Wholesale - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Financing Receivable, Modified [Line Items]
Carrying value of new TDRs		$ 108		$ 587
Commercial and industrial
Financing Receivable, Modified [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	$ 363		$ 1,500
Other
Financing Receivable, Modified [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	1		1
Secured by real estate
Financing Receivable, Modified [Line Items]
Additional commitments to lend to borrowers whose loans have been modified as FDM's	$ 1		$ 1