Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022		Jun. 30, 2021	Jun. 30, 2022		Jun. 30, 2021	Mar. 31, 2022	Dec. 31, 2021		Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 242			$ 242				$ 244
Net premium	452			452				498
Accrued interest receivable	356			356				332
Direct financing lease - interest income	7		$ 11	15		$ 23
Sales type lease - interest income	12		10	23		20
Allowance for loan and lease losses	2,014	[1]	$ 2,033	2,014	[1]	$ 2,033	$ 1,908	1,892	[1]	$ 2,208	$ 2,453
Federal Home Loan Bank Advances
Accounts, Notes, Loans and Financing Receivable
Loans pledged	16,600			16,600				15,300
FRB Loan
Accounts, Notes, Loans and Financing Receivable
Loans pledged	55,800			55,800				50,900
Commercial Leases
Accounts, Notes, Loans and Financing Receivable
Allowance for loan and lease losses	$ 15			$ 15				$ 15

[1] Includes $21 and $24 of other short-term investments, $267 and $322 of portfolio loans and leases, $(3) and $(2) of ALLL, $2 and $2 of other assets, $10 and $1 of other liabilities, and $200 and $263 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2022 and December 31, 2021, respectively. For further information, refer to Note 12.