Loans and Leases - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021		Mar. 31, 2020	Dec. 31, 2020		Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable
Unearned income	$ 279			$ 280
Net premium	262			251
Accrued interest receivable	381			350
Loans pledged at the FHLB	15,400			15,500
Loans pledged at the FRB	39,900			37,800
Direct financing lease - interest income	12		$ 18
Sales type lease - interest income	10		6
Allowance for loan and lease losses	2,208	[1]	$ 2,348	2,453	[1]	$ 1,202
Commercial Leases
Accounts, Notes, Loans and Financing Receivable
Allowance for loan and lease losses	$ 24			$ 29

[1] Includes $54 and $55 of other short-term investments, $633 and $756 of portfolio loans and leases, $(5) and $(7) of ALLL, $4 and $5 of other assets, $1 and $2 of other liabilities, and $540 and $656 of long-term debt from consolidated VIEs that are included in their respective captions above at March 31, 2021 and December 31, 2020, respectively. For further information, refer to Note 11.