Securitization Activities - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Assets securitized in a non-cash exchange for loans and investments	$ 39	$ 382	$ 149	$ 781
Net asset related to other continuing involvement	133		133		$ 72
Notional amount related to other continuing involvement	1,880		1,880		1,900
Outstanding Principal Amount	132,612		132,612		134,130
Fair value of retained interests	5,360		5,360		5,030
Corporate debt and other asset-backed
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	8,044		8,044		8,750
Installment
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Seller financing related to loans sold	2,700		2,700
Loans sold			3,240
Installment | Corporate debt and other asset-backed
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Outstanding Principal Amount	2,180		2,180
Other retained interests
Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items]
Fair value of retained interests	490		$ 490		$ 384
Weighted average life (years)			6 years 4 months 24 days		6 years 4 months 24 days
Maximum exposure to adverse changes in the value of other retained interests	$ 508		$ 508		$ 398