Securities - Schedule of Other Securities (Detail) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Schedule of Other Securities [Line Items] | ||
| Other securities | $ 693,502 | $ 676,300 |
| FRB and FHLB stock [Member] | ||
| Schedule of Other Securities [Line Items] | ||
| Other securities | 137,667 | 137,498 |
| Equity Securities With Readily Determinable Fair Values [Member] | ||
| Schedule of Other Securities [Line Items] | ||
| Other securities | 12,610 | 14,690 |
| Equity Securities Without Readily Determinable Fair Values [Member] | ||
| Schedule of Other Securities [Line Items] | ||
| Other securities | $ 543,225 | $ 524,112 |