Credit Concentrations - Credit Concentrations Included in Trading Cash Instruments and Investments (Detail) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended |
|---|---|---|
Mar. 31, 2026 |
Dec. 31, 2025 |
|
| U.S. government and agency obligations | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, credit risk, financial instrument, maximum exposure | $ 445,599 | $ 391,750 |
| Concentration risk, credit risk, financial instrument, maximum exposure, as a percentage of total assets | 21.60% | 21.70% |
| Non-U.S. government obligations | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, credit risk, financial instrument, maximum exposure | $ 152,163 | $ 112,031 |
| Concentration risk, credit risk, financial instrument, maximum exposure, as a percentage of total assets | 7.40% | 6.20% |