Business Segments - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue generated from certain contracts with customers included in non-interest income	$ 2,000	$ 1,800	$ 5,600	$ 5,100
Lease revenue	220	246	686	714
Payment Services [Member]
Rewards and Rebate Costs and Certain Partner Payments Included in Noninterest Income	$ 652	$ 525	$ 1,800	$ 1,500