Loans and Leases - Balances of Commercial Loan Portfolio Classes, Disaggregated by PD Grade (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	$ 62,781	$ 61,292
Commercial: | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1,669	4,124
Financing receivable, originated year two	3,953	5,832
Financing receivable, originated year three	5,363	3,664
Financing receivable, originated year four	3,314	1,743
Financing receivable, originated year five	1,489	1,805
Financing receivable, originated prior to year five	4,891	3,605
LMC	2,934	2,024
Revolving Loans	9,512	9,460
Revolving Loans Converted to Term Loans	327	376
Loans and leases	33,452	32,633
Commercial: | Commercial and industrial | PD Grade 1 -12
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1,623	4,008
Financing receivable, originated year two	3,772	5,637
Financing receivable, originated year three	5,184	3,506
Financing receivable, originated year four	3,139	1,636
Financing receivable, originated year five	1,446	1,665
Financing receivable, originated prior to year five	4,569	3,448
LMC	2,934	2,019
Revolving Loans	8,963	9,087
Revolving Loans Converted to Term Loans	278	327
Loans and leases	31,908	31,333
Commercial: | Commercial and industrial | PD Grade 13
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	45	75
Financing receivable, originated year two	133	60
Financing receivable, originated year three	71	64
Financing receivable, originated year four	65	56
Financing receivable, originated year five	18	101
Financing receivable, originated prior to year five	149	57
LMC	0	0
Revolving Loans	361	186
Revolving Loans Converted to Term Loans	28	0
Loans and leases	870	599
Commercial: | Commercial and industrial | PD Grade 14 ,15 and 16
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	1	41
Financing receivable, originated year two	48	135
Financing receivable, originated year three	108	94
Financing receivable, originated year four	110	51
Financing receivable, originated year five	25	39
Financing receivable, originated prior to year five	173	100
LMC	0	5
Revolving Loans	188	187
Revolving Loans Converted to Term Loans	21	49
Loans and leases	674	701
Commercial: | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases	14,669	14,216
Commercial: | Commercial real estate | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	288	858
Financing receivable, originated year two	1,050	3,476
Financing receivable, originated year three	3,856	3,652
Financing receivable, originated year four	3,678	1,259
Financing receivable, originated year five	1,214	1,566
Financing receivable, originated prior to year five	4,221	2,994
Revolving Loans	362	393
Revolving Loans Converted to Term Loans	0	18
Loans and leases	14,669	14,216
Commercial: | Commercial real estate | PD Grade 1 -12 | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	288	853
Financing receivable, originated year two	1,046	3,473
Financing receivable, originated year three	3,580	3,518
Financing receivable, originated year four	3,470	1,162
Financing receivable, originated year five	1,071	1,216
Financing receivable, originated prior to year five	3,635	2,853
Revolving Loans	356	393
Revolving Loans Converted to Term Loans	0	18
Loans and leases	13,446	13,486
Commercial: | Commercial real estate | PD Grade 13 | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	0	5
Financing receivable, originated year two	1	1
Financing receivable, originated year three	209	129
Financing receivable, originated year four	94	86
Financing receivable, originated year five	31	175
Financing receivable, originated prior to year five	134	82
Revolving Loans	0	0
Revolving Loans Converted to Term Loans	0	0
Loans and leases	469	478
Commercial: | Commercial real estate | PD Grade 14 ,15 and 16 | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, originated year one	0	0
Financing receivable, originated year two	3	2
Financing receivable, originated year three	67	5
Financing receivable, originated year four	114	11
Financing receivable, originated year five	112	175
Financing receivable, originated prior to year five	452	59
Revolving Loans	6	0
Revolving Loans Converted to Term Loans	0	0
Loans and leases	$ 754	$ 252