Business Segments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue generated from certain contracts with customers included in non-interest income	$ 1,900	$ 1,600	$ 3,600	$ 3,300
Lease revenue	238	230	466	468
Payment Services [Member]
Rewards and Rebate Costs and Certain Partner Payments Included in Noninterest Income	$ 633	$ 445	$ 1,200	$ 975