Credit Concentrations - Credit Concentrations Included in Trading Cash Instruments and Investments (Detail) - USD ($) $ in Millions |
6 Months Ended | 12 Months Ended |
|---|---|---|
Jun. 30, 2026 |
Dec. 31, 2025 |
|
| U.S. government and agency obligations | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, credit risk, financial instrument, maximum exposure | $ 467,264 | $ 391,750 |
| Concentration risk, credit risk, financial instrument, maximum exposure, as a percentage of total assets | 22.00% | 21.70% |
| Non-U.S. government obligations | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, credit risk, financial instrument, maximum exposure | $ 152,962 | $ 112,031 |
| Concentration risk, credit risk, financial instrument, maximum exposure, as a percentage of total assets | 7.20% | 6.20% |