Unsecured Borrowings - Schedule of Unsecured Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Debt Disclosure [Abstract]
Unsecured short-term borrowings	$ 51,850	$ 46,955
Unsecured long-term borrowings	239,965	254,092
Total	$ 291,815	$ 301,047

Carrying value as of the balance sheet date of uncollateralized debt obligation (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_UnsecuredLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant