Loans and Leases - Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Movement Schedule Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period	$ 13	$ 16
Accretion	(6)	(10)
Adjustment for payoffs	(2)	(4)
Adjustment for charge-offs	(1)	(1)
Increase/(decrease) in accretable yield	6	13
Other	0	(1)
Balance, end of period	$ 10	$ 13