Credit Quality and the Allowance for Loan and Lease Losses - Summary of Recorded Investment in Portfolio Loans and Leases by Age and Class (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	$ 117,900	$ 110,158
Commercial
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	75,778	70,268
90 Days Past Due and Still Accruing	26	19
Commercial | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	75,555	70,132
Commercial | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	223	136
Commercial | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	172	81
Commercial | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	51	55
Commercial | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	56,437	51,659
90 Days Past Due and Still Accruing	16	17
Loans and leases related to SBA Paycheck Protection Program of CARES Act	210	1,300
Commercial | Commercial and industrial loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	56,256	51,549
Commercial | Commercial and industrial loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	181	110
Commercial | Commercial and industrial loans | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	144	61
Loans and leases related to SBA Paycheck Protection Program of CARES Act	3	20
Commercial | Commercial and industrial loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	37	49
Loans and leases related to SBA Paycheck Protection Program of CARES Act	8	6
Commercial | Commercial mortgage owner-occupied loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,067	4,709
90 Days Past Due and Still Accruing	0	1
Commercial | Commercial mortgage owner-occupied loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,050	4,701
Commercial | Commercial mortgage owner-occupied loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	17	8
Commercial | Commercial mortgage owner-occupied loans | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	16	4
Commercial | Commercial mortgage owner-occupied loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	1	4
Commercial | Commercial mortgage nonowner-occupied loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,880	5,607
90 Days Past Due and Still Accruing	0	0
Commercial | Commercial mortgage nonowner-occupied loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,876	5,606
Commercial | Commercial mortgage nonowner-occupied loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	4	1
Commercial | Commercial mortgage nonowner-occupied loans | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	3	0
Commercial | Commercial mortgage nonowner-occupied loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	1	1
Commercial | Commercial construction loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,573	5,241
90 Days Past Due and Still Accruing	0	1
Commercial | Commercial construction loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	5,571	5,241
Commercial | Commercial construction loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	2	0
Commercial | Commercial construction loans | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	0	0
Commercial | Commercial construction loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	2	0
Commercial | Commercial leases
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	2,821	3,052
90 Days Past Due and Still Accruing	10	0
Commercial | Commercial leases | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	2,802	3,035
Commercial | Commercial leases | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	19	17
Commercial | Commercial leases | 30 to 89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	9	16
Commercial | Commercial leases | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	$ 10	$ 1