Business Segments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue generated from certain contracts with customers included in non-interest income	$ 1,800	$ 1,900	$ 5,100	$ 5,500
Lease revenue	246	257	714	742
Payment Services [Member]
Rewards and Rebate Costs and Certain Partner Payments Included in Noninterest Income	$ 525	$ 572	$ 1,500	$ 1,700