Loans - Schedule of Activity In The Allowance For Loan Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 67	$ 54	$ 53
Provision for loan losses	10	15	2
Charge-offs	(3)	(2)	(1)
Ending balance	$ 74	$ 67	$ 54