Investment Securities - Amount of Interest Income from Taxable and Non-Taxable Investment Securities (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Interest Income, Securities, Operating, by Taxable Status [Abstract]
Taxable	$ 1,074	$ 793	$ 3,067	$ 2,171
Non-taxable	78	74	236	219
Total interest income from investment securities	$ 1,152	$ 867	$ 3,303	$ 2,390