Commitments and Contingencies - Commitments and Contingent Liabilities Outstanding (Detail) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Commitments to extend credit
Commercial and industrial	$ 33,065	$ 31,521
Commercial real estate loans to be sold	784	479
Other commercial real estate	2,345	2,697
Residential real estate loans to be sold	224	190
Other residential real estate	648	517
Home equity lines of credit	7,933	7,933
Credit cards	6,243	6,087
Other	287	244
Standby letters of credit	2,254	2,260
Commercial letters of credit	53	58
Financial guarantees and indemnification contracts	4,429	4,335
Commitments to sell real estate loans	$ 1,313	$ 1,142