Variable Interest Entities - Summary of Credit Risk Transfer Agreements (Parenthetical) (Detail) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Transfer Of Financial Assets Accounted For As Sales [Line Items] | ||
| Deposits securing CRT strips and derivatives liabilities | $ 5.4 | $ 6.0 |