Loans and Leases - Loans and Leases Classified by Primary Purpose (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Loans and leases held for sale:
Loans and leases held for sale	$ 640	$ 378
Portfolio loans and leases:
Total portfolio loans and leases	119,791	117,234
Commercial
Portfolio loans and leases:
Total portfolio loans and leases	73,293	72,746
Commercial | Commercial and industrial loans
Loans and leases held for sale:
Loans and leases held for sale	15	41
Portfolio loans and leases:
Total portfolio loans and leases	52,271	53,270
Commercial | Commercial mortgage loans
Loans and leases held for sale:
Loans and leases held for sale	22	0
Portfolio loans and leases:
Total portfolio loans and leases	12,246	11,276
Commercial | Commercial construction loans
Loans and leases held for sale:
Loans and leases held for sale	29	0
Portfolio loans and leases:
Total portfolio loans and leases	5,588	5,621
Commercial | Commercial leases
Loans and leases held for sale:
Loans and leases held for sale	0	3
Portfolio loans and leases:
Total portfolio loans and leases	3,188	2,579
Consumer
Portfolio loans and leases:
Total portfolio loans and leases	46,498	44,488
Consumer | Residential mortgage loans
Loans and leases held for sale:
Loans and leases held for sale	574	334
Portfolio loans and leases:
Total portfolio loans and leases	17,543	17,026
Consumer | Home equity
Portfolio loans and leases:
Total portfolio loans and leases	4,188	3,916
Consumer | Indirect secured consumer loans
Portfolio loans and leases:
Total portfolio loans and leases	16,313	14,965
Consumer | Credit card
Portfolio loans and leases:
Total portfolio loans and leases	1,734	1,865
Consumer | Solar energy installation loans
Portfolio loans and leases:
Total portfolio loans and leases	4,202	3,728
Consumer | Other consumer loans
Portfolio loans and leases:
Total portfolio loans and leases	$ 2,518	$ 2,988