Loans and Leases - Loans and Leases Classified by Primary Purpose (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Loans and leases held for sale:
Loans and leases held for sale	[1]	$ 4,741	$ 1,400
Portfolio loans and leases:
Commercial and industrial loans		49,665	50,542
Commercial mortgage loans		10,602	10,963
Commercial construction loans		5,815	5,090
Commercial leases		2,915	3,363
Residential mortgage loans		15,928	16,724
Home equity		5,183	6,083
Indirect secured consumer loans		13,653	11,538
Credit card		2,007	2,532
Other consumer loans		3,014	2,723
Total portfolio loans and leases	[2],[3]	108,782	109,558
Commercial leases
Loans and leases held for sale:
Loans and leases held for sale		39	0
Residential mortgage loans
Loans and leases held for sale:
Loans and leases held for sale		4,465	1,264
Commercial
Portfolio loans and leases:
Total portfolio loans and leases		68,997	69,958
Commercial | Commercial and industrial loans
Loans and leases held for sale:
Loans and leases held for sale		230	135
Portfolio loans and leases:
Total portfolio loans and leases		49,665
Loans and leases related to SBA Paycheck Protection Program of CARES Act		4,800
Commercial | Commercial mortgage loans
Loans and leases held for sale:
Loans and leases held for sale		7	1
Commercial | Commercial leases
Portfolio loans and leases:
Total portfolio loans and leases		2,915
Consumer
Portfolio loans and leases:
Total portfolio loans and leases		39,785	$ 39,600
Consumer | Residential mortgage loans | GNMA loans
Portfolio loans and leases:
Total portfolio loans and leases		$ 39

[1] Includes $1,481 and $1,264 of residential mortgage loans held for sale measured at fair value at December 31, 2020 and 2019, respectively.

[2] Includes $161 and $183 of residential mortgage loans measured at fair value at December 31, 2020 and 2019, respectively.

[3] Includes $55 and $74 of other short-term investments, $756 and $1,354 of portfolio loans and leases, $(7) and $(7) of ALLL, $5 and $8 of other assets, $2 and $2 of other liabilities and $656 and $1,253 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2020 and 2019, respectively. For further information, refer to Note 13.