Securitization Activities - Amount of Financial Assets Securitized and Cash Flows Received on Retained Interests (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Transfers and Servicing [Abstract]
Residential mortgages	$ 6,128	$ 9,888	$ 25,069	$ 19,894
Commercial mortgages	2,306	3,066	13,820	13,832
Other financial assets	902	2,353	3,519	4,017
Total financial assets securitized	9,336	15,307	42,408	37,743
Retained interests cash flows	$ 125	$ 204	$ 428	$ 452