Fair Value - Unfunded Loan and Lease Commitments and Letters of Credit (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Unfunded loan and lease commitments and letters of credit | ||
| Aggregate commitments to extend credit, standby letters of credit and commercial letters of credit | $ 6,800.0 | $ 6,900.0 |
| Significant Unobservable Inputs (Level 3) | ||
| Unfunded loan and lease commitments and letters of credit | ||
| Aggregate commitments to extend credit, standby letters of credit and commercial letters of credit | 6,800.0 | 6,900.0 |
| Estimated fair value of unfunded loan and lease commitments and letters of credit | $ 53.1 | $ 49.7 |