Loans and ACL - Aging Analysis of Loans and Leases (Details) - USD ($) $ in Millions		Jun. 30, 2022	Dec. 31, 2021
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 303,662	$ 289,513
Nonperforming		1,090	1,090
Total loans and leases		303,662	289,513
Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		298,694	284,449
Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		2,091	2,044
Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,787	1,930
Commercial: | Commercial and industrial
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		149,840	138,762
Nonperforming		393	394
Total loans and leases		149,840	138,762
Commercial: | Commercial and industrial | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		149,197	138,225
Commercial: | Commercial and industrial | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		223	130
Commercial: | Commercial and industrial | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		27	13
Commercial: | CRE
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		22,149	23,951
Nonperforming		19	29
Total loans and leases		22,149	23,951
Commercial: | CRE | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		22,117	23,902
Commercial: | CRE | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		10	20
Commercial: | CRE | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		3	0
Commercial: | Commercial construction
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		5,157	4,971
Nonperforming		0	7
Total loans and leases		5,157	4,971
Commercial: | Commercial construction | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		5,150	4,962
Commercial: | Commercial construction | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		4	2
Commercial: | Commercial construction | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		3	0
Consumer: | Residential mortgage
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		50,903	47,852
Nonperforming		269	296
Total loans and leases		50,903	47,852
Consumer: | Residential mortgage | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		49,188	46,033
Consumer: | Residential mortgage | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		535	514
Consumer: | Residential mortgage | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	[1]	911	1,009
Consumer: | Residential mortgage | Financial Asset, Equal to or Greater than 90 Days Past Due | Loans Insured or Guaranteed by US Government Authorities
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		884	978
Consumer: | Residential home equity and direct
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		25,345	25,066
Nonperforming		159	141
Total loans and leases		25,345	25,066
Consumer: | Residential home equity and direct | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		25,020	24,809
Consumer: | Residential home equity and direct | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		156	107
Consumer: | Residential home equity and direct | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		10	9
Consumer: | Indirect auto
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		27,419	26,441
Nonperforming		244	218
Total loans and leases		27,419	26,441
Consumer: | Indirect auto | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		26,590	25,615
Consumer: | Indirect auto | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		584	607
Consumer: | Indirect auto | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		1	1
Consumer: | Indirect other
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		11,961	10,883
Nonperforming		6	5
Total loans and leases		11,961	10,883
Consumer: | Indirect other | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		11,874	10,811
Consumer: | Indirect other | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		78	64
Consumer: | Indirect other | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		3	3
Consumer: | Student
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		6,144	6,780
Nonperforming		0	0
Total loans and leases		6,144	6,780
Consumer: | Student | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,890	5,357
Consumer: | Student | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		453	555
Consumer: | Student | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	[1]	801	868
Consumer: | Student | Financial Asset, Equal to or Greater than 90 Days Past Due | Loans Insured or Guaranteed by US Government Authorities
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		796	864
Credit card
Financing Receivable [Line Items]
Nonperforming		0	0
Total loans and leases		4,744	4,807
Credit card | Financial Asset, Not Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		4,668	4,735
Credit card | Financing Receivables 30 To 89 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		48	45
Credit card | Financial Asset, Equal to or Greater than 90 Days Past Due
Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss		$ 28	$ 27

[1] (1)Includes government guaranteed loans of $884 million in the residential mortgage portfolio and $796 million in the student portfolio.