Loans and Related Allowance for Credit Losses, Significant Activity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Loans and Allowance for Credit Losses, Significant Activity [Abstract]
Purchases	$ 100	$ 49
Sales	(582)	(461)
Transfers (to)/from LHFS	12	(372)
Total Commercial [Member]
Loans and Allowance for Credit Losses, Significant Activity [Abstract]
Purchases	100	48
Sales	(582)	(273)
Transfers (to)/from LHFS	21	(435)
Total Consumer [Member]
Loans and Allowance for Credit Losses, Significant Activity [Abstract]
Purchases	0	1
Sales	0	(188)
Transfers (to)/from LHFS	$ (9)	$ 63