Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024		Dec. 31, 2023		Dec. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned income	$ 380		$ 272
Accrued interest receivable	566		593
Net premium (discount)	$ (324)		$ (395)
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	$ 40		$ 26		$ 29
Sales type lease - interest income	82		63		50
Allowance for loan and lease losses	2,352	[1]	2,322	[1]	$ 2,194	$ 1,892
Commercial leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan and lease losses	16		13
Solar energy installation loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net premium (discount)	(901)		(865)
FHLB advances
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged	15,100		14,500
FRB Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged	$ 55,300		$ 49,300

[1] Includes $51 and $55 of other short-term investments, $1,000 and $1,573 of portfolio loans and leases, $(19) and $(28) of ALLL, $5 and $10 of other assets, $12 and $14 of other liabilities and $889 and $1,409 of long-term debt from consolidated VIEs that are included in their respective captions above at December 31, 2024 and 2023, respectively. For further information, refer to Note 12.