Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2022		Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021		Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 241			$ 241				$ 244
Net premium	355			355				498
Accrued interest receivable	403			403				332
Direct financing lease - interest income	7		$ 10	22		$ 33
Sales type lease - interest income	13		11	36		31
Allowance for loan and lease losses	2,099	[1]	$ 1,954	2,099	[1]	$ 1,954	$ 2,014	1,892	[1]	$ 2,033	$ 2,453
Commercial Leases
Accounts, Notes, Loans and Financing Receivable
Allowance for loan and lease losses	16			16				15
Federal Home Loan Bank Advances
Accounts, Notes, Loans and Financing Receivable
Loans pledged	16,700			16,700				15,300
FRB Loan
Accounts, Notes, Loans and Financing Receivable
Loans pledged	$ 56,600			$ 56,600				$ 50,900

[1] Includes $19 and $24 of other short-term investments, $223 and $322 of portfolio loans and leases, $(3) and $(2) of ALLL, $2 and $2 of other assets, $9 and $1 of other liabilities, and $156 and $263 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2022 and December 31, 2021, respectively. For further information, refer to Note 12.