Other financial liabilities designated at fair value (Detail) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Disclosure Of Financial Liabilities [Line Items] | ||
| Financial liabilities related to unit-linked investment contracts | $ 22,838 | $ 21,052 |
| Securities financing transactions | 4,259 | 3,848 |
| Over-the-counter debt instruments and other | 2,730 | 3,284 |
| Funding from UBS Group AG | 7,508 | 7,104 |
| Total other financial liabilities designated at fair value | $ 37,335 | $ 35,287 |