Loans and Leases - Loans and Leases Classified by Primary Purpose (Details) - USD ($) $ in Millions		Jun. 30, 2024	Dec. 31, 2023
Loans and leases held for sale:
Loans and leases held for sale (includes $512 and $334 of residential mortgage loans measured at fair value)		$ 537	$ 378
Portfolio loans and leases:
Total portfolio loans and leases	[1]	116,579	117,234
Commercial
Portfolio loans and leases:
Total portfolio loans and leases		71,783	72,746
Commercial | Commercial and industrial loans
Loans and leases held for sale:
Loans and leases held for sale (includes $512 and $334 of residential mortgage loans measured at fair value)		22	41
Portfolio loans and leases:
Total portfolio loans and leases		51,840	53,270
Commercial | Commercial leases
Loans and leases held for sale:
Loans and leases held for sale (includes $512 and $334 of residential mortgage loans measured at fair value)		3	3
Portfolio loans and leases:
Total portfolio loans and leases		2,708	2,579
Commercial | Commercial mortgage loans
Portfolio loans and leases:
Total portfolio loans and leases		11,429	11,276
Commercial | Commercial construction loans
Portfolio loans and leases:
Total portfolio loans and leases		5,806	5,621
Consumer
Portfolio loans and leases:
Total portfolio loans and leases		44,796	44,488
Consumer | Residential mortgage loans
Loans and leases held for sale:
Loans and leases held for sale (includes $512 and $334 of residential mortgage loans measured at fair value)		512	334
Portfolio loans and leases:
Total portfolio loans and leases		17,040	17,026
Consumer | Home equity
Portfolio loans and leases:
Total portfolio loans and leases		3,969	3,916
Consumer | Indirect secured consumer loans
Portfolio loans and leases:
Total portfolio loans and leases		15,442	14,965
Consumer | Credit card
Portfolio loans and leases:
Total portfolio loans and leases		1,733	1,865
Consumer | Solar energy installation loans
Portfolio loans and leases:
Total portfolio loans and leases		3,951	3,728
Consumer | Other consumer loans
Portfolio loans and leases:
Total portfolio loans and leases		$ 2,661	$ 2,988

[1] Includes $52 and $55 of other short-term investments, $1,272 and $1,573 of portfolio loans and leases, $(23) and $(28) of ALLL, $7 and $10 of other assets, $13 and $14 of other liabilities and $1,136 and $1,409 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2024 and December 31, 2023, respectively. For further information, refer to Note 11.