Allowance for Credit Losses (Changes in Allowance for Credit Losses Related to Loans) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | 12 Months Ended | ||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| LOANS | |||||
| Balance at Beginning of Period | $ 167.1 | $ 162.4 | $ 168.0 | $ 178.7 | $ 178.7 |
| Charge-Offs | (0.1) | (0.3) | (0.4) | (11.4) | (15.5) |
| Recoveries | 0.4 | 0.4 | 0.9 | 1.1 | |
| Net Recoveries (Charge-Offs) | 0.3 | 0.1 | 0.5 | (10.3) | |
| Provision for Credit Losses | 13.1 | 5.2 | 12.0 | (0.7) | |
| Balance at End of Period | 180.5 | 167.7 | 180.5 | 167.7 | 168.0 |
| UNDRAWN LOAN COMMITMENTS AND STANDBY LETTERS OF CREDIT | |||||
| Balance at Beginning of Period | 32.8 | 25.2 | 30.4 | 26.9 | 26.9 |
| Charge-Offs | 0.0 | 0.0 | 0.0 | 0.0 | |
| Recoveries | 0.0 | 0.0 | 0.0 | 0.0 | |
| Net Recoveries (Charge-Offs) | 0.0 | 0.0 | 0.0 | 0.0 | |
| Provision for Credit Losses | 1.9 | 4.3 | 4.3 | 2.6 | |
| Balance at End of Period | 34.7 | 29.5 | 34.7 | 29.5 | 30.4 |
| COMMERCIAL | |||||
| LOANS | |||||
| Balance at Beginning of Period | 133.6 | 131.7 | 138.5 | 146.8 | 146.8 |
| Charge-Offs | 0.0 | 0.0 | (0.3) | (11.0) | (15.1) |
| Recoveries | 0.0 | 0.0 | 0.1 | 0.0 | |
| Net Recoveries (Charge-Offs) | 0.0 | 0.0 | (0.2) | (11.0) | |
| Provision for Credit Losses | 12.2 | 5.2 | 7.5 | 1.1 | |
| Balance at End of Period | 145.8 | 136.9 | 145.8 | 136.9 | 138.5 |
| UNDRAWN LOAN COMMITMENTS AND STANDBY LETTERS OF CREDIT | |||||
| Balance at Beginning of Period | 30.7 | 22.5 | 28.3 | 24.9 | 24.9 |
| Charge-Offs | 0.0 | 0.0 | 0.0 | 0.0 | |
| Recoveries | 0.0 | 0.0 | 0.0 | 0.0 | |
| Net Recoveries (Charge-Offs) | 0.0 | 0.0 | 0.0 | 0.0 | |
| Provision for Credit Losses | 1.8 | 4.7 | 4.2 | 2.3 | |
| Balance at End of Period | 32.5 | 27.2 | 32.5 | 27.2 | 28.3 |
| PERSONAL | |||||
| LOANS | |||||
| Balance at Beginning of Period | 33.5 | 30.7 | 29.5 | 31.9 | 31.9 |
| Charge-Offs | (0.1) | (0.3) | (0.1) | (0.4) | (0.4) |
| Recoveries | 0.4 | 0.4 | 0.8 | 1.1 | |
| Net Recoveries (Charge-Offs) | 0.3 | 0.1 | 0.7 | 0.7 | |
| Provision for Credit Losses | 0.9 | 0.0 | 4.5 | (1.8) | |
| Balance at End of Period | 34.7 | 30.8 | 34.7 | 30.8 | 29.5 |
| UNDRAWN LOAN COMMITMENTS AND STANDBY LETTERS OF CREDIT | |||||
| Balance at Beginning of Period | 2.1 | 2.7 | 2.1 | 2.0 | 2.0 |
| Charge-Offs | 0.0 | 0.0 | 0.0 | 0.0 | |
| Recoveries | 0.0 | 0.0 | 0.0 | 0.0 | |
| Net Recoveries (Charge-Offs) | 0.0 | 0.0 | 0.0 | 0.0 | |
| Provision for Credit Losses | 0.1 | (0.4) | 0.1 | 0.3 | |
| Balance at End of Period | $ 2.2 | $ 2.3 | $ 2.2 | $ 2.3 | $ 2.1 |