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		Dec. 31, 2023	Dec. 31, 2022
Financing Receivable, Recorded Investment, Past Due
Loans and Leases	[1],[2]	$ 117,234	$ 121,480
Commercial
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		72,746	76,389
90 Days Past Due and Still Accruing		8	13
Commercial | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		72,547	76,211
Commercial | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		199	178
Commercial | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		93	129
Commercial | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		106	49
Commercial | Commercial and industrial loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		53,270	57,232
90 Days Past Due and Still Accruing		8	11
Commercial | Commercial and industrial loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		53,107	57,092
Commercial | Commercial and industrial loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		163	140
Commercial | Commercial and industrial loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		61	98
Commercial | Commercial and industrial loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		102	42
Commercial | Commercial mortgage owner-occupied loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		5,200	5,258
90 Days Past Due and Still Accruing		0	0
Commercial | Commercial mortgage owner-occupied loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		5,196	5,241
Commercial | Commercial mortgage owner-occupied loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		4	17
Commercial | Commercial mortgage owner-occupied loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		1	14
Commercial | Commercial mortgage owner-occupied loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		3	3
Commercial | Commercial mortgage nonowner-occupied loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		6,076	5,762
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		6,061	5,756
Commercial | Commercial mortgage nonowner-occupied loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		15	6
Commercial | Commercial mortgage nonowner-occupied loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		14	6
Commercial | Commercial mortgage nonowner-occupied loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		1	0
Commercial | Commercial construction loans
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		5,621	5,433
90 Days Past Due and Still Accruing		0	0
Commercial | Commercial construction loans | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		5,621	5,424
Commercial | Commercial construction loans | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		0	9
Commercial | Commercial construction loans | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		0	7
Commercial | Commercial construction loans | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		0	2
Commercial | Commercial leases
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		2,579	2,704
90 Days Past Due and Still Accruing		0	2
Commercial | Commercial leases | Current
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		2,562	2,698
Commercial | Commercial leases | Total Past Due
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		17	6
Commercial | Commercial leases | 30-89 Days
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		17	4
Commercial | Commercial leases | 90 Days or More
Financing Receivable, Recorded Investment, Past Due
Loans and Leases		$ 0	$ 2

[1] Includes $55 and $17 of other short-term investments, $1,573 and $185 of portfolio loans and leases, $(28) and $(2) of ALLL, $10 and $2 of other assets, $14 and $9 of other liabilities and $1,409 and $118 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2023 and 2022, respectively. For further information, refer to Note 12.

[2] Includes $116 and $123 of residential mortgage loans measured at fair value at December 31, 2023 and 2022, respectively.