Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned income	$ 272		$ 238
Net premium (discount)	(395)		146
Accrued interest receivable	$ 593		$ 518
Direct Financing Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest and Dividend Income, Operating		Interest and Dividend Income, Operating		Interest and Dividend Income, Operating
Sales-Type Lease, Lease Income, Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest and Dividend Income, Operating		Interest and Dividend Income, Operating		Interest and Dividend Income, Operating
Direct financing lease - interest income	$ 26		$ 29		$ 42
Sales type lease - interest income	63		50		42
Allowance for loan and lease losses	2,322	[1]	2,194	[1]	$ 1,892	$ 2,453
FHLB advances
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged	14,500		15,900
FRB Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged	49,300		57,100
Commercial Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	$ 13		$ 15

[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.