Unsecured Borrowings - Schedule of Unsecured Borrowings (Detail) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Debt Disclosure [Abstract]
Unsecured short-term borrowings	$ 80,878	$ 70,459
Unsecured long-term borrowings	315,426	285,500
Total	$ 396,304	$ 355,959

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
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-SubTopic 10
-Topic 210
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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