Loans and Leases - Loans and Leases Classified by Primary Purpose (Details) - USD ($) $ in Millions		Sep. 30, 2025	Dec. 31, 2024
Loans and leases held for sale:
Loans held for sale		$ 576	$ 640
Portfolio loans and leases:
Total portfolio loans and leases	[1]	123,130	119,791
Commercial
Portfolio loans and leases:
Total portfolio loans and leases		74,423	73,293
Commercial | Commercial and industrial loans
Loans and leases held for sale:
Loans held for sale		8	15
Portfolio loans and leases:
Total portfolio loans and leases		53,947	52,271
Commercial | Commercial mortgage loans
Loans and leases held for sale:
Loans held for sale		0	22
Portfolio loans and leases:
Total portfolio loans and leases		11,932	12,246
Commercial | Commercial construction loans
Loans and leases held for sale:
Loans held for sale		0	29
Portfolio loans and leases:
Total portfolio loans and leases		5,326	5,588
Commercial | Commercial leases
Portfolio loans and leases:
Total portfolio loans and leases		3,218	3,188
Consumer
Portfolio loans and leases:
Total portfolio loans and leases		48,707	46,498
Consumer | Residential mortgage loans
Loans and leases held for sale:
Loans held for sale		565	574
Portfolio loans and leases:
Total portfolio loans and leases		17,644	17,543
Consumer | Home equity
Portfolio loans and leases:
Total portfolio loans and leases		4,678	4,188
Consumer | Indirect secured consumer loans
Portfolio loans and leases:
Total portfolio loans and leases		17,885	16,313
Consumer | Credit card
Portfolio loans and leases:
Total portfolio loans and leases		1,692	1,734
Consumer | Solar energy installation loans
Portfolio loans and leases:
Total portfolio loans and leases		4,432	4,202
Consumer | Other consumer loans
Portfolio loans and leases:
Total portfolio loans and leases		2,376	2,518
Consumer | Credit Card
Loans and leases held for sale:
Loans held for sale		$ 3	$ 0

[1] Includes $42 and $51 of other short-term investments, $649 and $1,000 of portfolio loans and leases, $(11) and $(19) of ALLL, $4 and $5 of other assets, $11 and $12 of other liabilities and $563 and $889 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2025 and December 31, 2024, respectively. For further information, refer to Note 7.