Investment Securities - Proceeds from Calls and Sales, Realized Gains and Losses and Interest Income Narrative (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Proceeds from calls and sales of investment securities | ||||
| Proceeds from calls of investment securities | $ 15.3 | $ 0.5 | $ 27.9 | $ 40.6 |
| Proceeds from sales of investment securities | 0.0 | 0.0 | 0.0 | 0.0 |
| Interest income from taxable and nontaxable investment securities | ||||
| Interest income from taxable investment securities | 28.0 | 25.7 | 54.8 | 52.4 |
| Interest income from non-taxable investment securities | $ 3.0 | $ 3.1 | $ 6.1 | $ 6.2 |