Loans and Leases - Net Charge-Offs (Recoveries (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	$ 130	$ 78	$ 252	$ 156
Residential mortgage loans
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	1	(1)	2	0
Commercial | Commercial and industrial loans
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	65	20	115	38
Commercial | Commercial mortgage loans
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	2	0	4	(1)
Commercial | Commercial leases
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	11	3	16	3
Consumer | Home equity
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	1	3	4	6
Consumer | Indirect secured consumer loans
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	7	7	20	20
Consumer | Credit card
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	34	35	71	68
Consumer | Other consumer loans
Assets that Continue to be Recognized, Securitized or Asset-backed Financing Arrangement Assets and any Other Financial Assets Managed Together
Net Charge-Offs	$ 9	$ 11	$ 20	$ 22