Other Service charges, commissions and fees (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Service charges, commissions and fees [Line Items]
Other service charges, commissions, and fees	$ 58	$ 55	$ 113	$ 110
Revenue Recognition [Member]
Other Service charges, commissions and fees [Line Items]
Other Service Charges	3	4	7	7
Other service charges, commissions, and fees	$ 45	$ 46	$ 88	$ 89