Commitments and Contingent Liabilities - Commitments to Extend Credit, Guarantees and Various Letters of Credit Outstanding (Detail) - USD ($) $ in Thousands |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Commitments and Contingencies Disclosure [Abstract] | ||
| Lines of credit | $ 5,989,423 | $ 5,231,344 |
| Loans approved but not closed | 752,512 | 469,694 |
| Overdraft limits | 544,105 | 556,063 |
| Letters of credit | 59,164 | 56,030 |
| Contingent obligations and other guarantees | $ 35,964 | $ 36,179 |