Credit Concentrations - U.S. Government and Agency Obligations and Non-U.S. Government and Agency Obligations that Collateralize Resale Agreements and Securities Borrowed Transactions (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 | $ 101,527 | $ 104,073 |
| Non-U.S. government and agency obligations | ||
| Concentration Risk [Line Items] | ||
| Concentration risk, credit risk, financial instrument, maximum exposure | $ 61,183 | $ 54,213 |