Fair Value Option - Gains and Losses on Other Financial Assets and Financial Liabilities at Fair Value (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value option gains/(losses)	$ (5,713)	$ (5,157)	$ (3,355)	$ (6,229)
Unsecured short-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value option gains/(losses)	(2,179)	(2,229)	(803)	(1,812)
Unsecured long-term borrowings
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value option gains/(losses)	(3,518)	(2,652)	(2,873)	(3,936)
Other
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value option gains/(losses)	$ (16)	$ (276)	$ 321	$ (481)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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