| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Interest income | | | | | | | | |
| Loans | 31.2 | 28.7 | 27.0 | 23.2 | 22.0 | 21.4 | 21.5 | 19.9 |
| Investment securities - taxable | 4.4 | 4.4 | 3.8 | 2.9 | 2.0 | 1.6 | 1.6 | 1.5 |
| Investment securities - tax-exempt | 0.9 | 0.9 | 1.1 | 1.2 | 1.1 | 0.7 | 0.7 | 0.7 |
| Short-term investments | 0.4 | 0.3 | | | 0.2 | 0.1 | | |
| Total interest income | 36.9 | 34.3 | 32.1 | 27.4 | 25.4 | 23.8 | 23.9 | 22.2 |
| |
| Interest expense | | | | | | | | |
| Deposits | 8.6 | 6.2 | 3.6 | 1.4 | 0.7 | 0.7 | 0.8 | 0.9 |
| Securities sold under agreements to repurchase and federal funds purchased | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| FHLB advances and other borrowings | 1.4 | 1.3 | | 0.1 | 0.0 | 0.0 | | 0.1 |
| Subordinated notes | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
| Total interest expense | 10.5 | 8.0 | 4.6 | 2.0 | 1.2 | 1.2 | 1.3 | 1.6 |
| Net interest income | 26.4 | 26.3 | 27.5 | 25.5 | 24.1 | 22.6 | 22.6 | 20.6 |
| Provision for credit losses | 0.4 | 0.7 | | | 1.8 | 0.3 | | |
| Net interest income after provision for credit losses | 26.0 | 25.6 | 26.9 | 24.0 | 22.3 | 22.3 | 21.5 | 20.3 |
| |
| Noninterest income | | | | | | | | |
| Service charges on deposit accounts | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 0.9 | 0.8 | 0.8 |
| Interchange income | 1.0 | 1.0 | 1.0 | 1.0 | 1.1 | 1.0 | 1.1 | 1.0 |
| Other service charges, commissions and fees | 0.3 | 0.2 | | | 0.2 | 0.2 | | |
| Swap fee income | 0.2 | | 0.7 | 0.2 | 0.8 | 1.0 | 0.2 | 0.1 |
| Trust and investment management income | 1.9 | 1.9 | 1.8 | 2.0 | 1.9 | 1.9 | 2.0 | 1.9 |
| Brokerage income | 0.9 | 0.9 | 0.8 | 0.9 | 1.0 | 0.9 | 0.9 | 1.0 |
| Mortgage banking activities | 0.1 | 0.5 | 0.2 | -1.0 | 0.5 | 0.7 | 1.2 | 1.3 |
| Income from life insurance | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 |
| Investment securities losses | 0.0 | 0.0 | | | 0.0 | -0.1 | | |
| Other income | 1.1 | 0.1 | 0.1 | 1.1 | 0.2 | 0.5 | 0.4 | 0.3 |
| Total noninterest income | 7.2 | 6.1 | 6.2 | 6.1 | 7.2 | 7.5 | 7.3 | 7.7 |
| |
| Noninterest expenses | | | | | | | | |
| Salaries and employee benefits | 13.1 | 12.2 | 12.7 | 12.7 | 11.3 | 11.3 | 12.1 | 11.5 |
| Occupancy | 1.1 | 1.1 | 1.1 | 1.2 | 1.1 | 1.3 | 1.2 | 1.2 |
| Furniture and equipment | 1.2 | 1.2 | 1.3 | 1.2 | 1.3 | 1.3 | 1.3 | 1.2 |
| Data processing | 1.2 | 1.2 | 1.2 | 1.2 | 1.2 | 1.1 | 1.0 | 1.0 |
| Automated teller and interchange fees | 0.3 | 0.3 | | | 0.3 | 0.3 | | |
| Advertising and bank promotions | 0.9 | 0.4 | 0.8 | 0.3 | 0.9 | 0.4 | 0.7 | 0.7 |
| FDIC insurance | 0.5 | 0.5 | 0.3 | 0.3 | 0.2 | 0.3 | 0.2 | 0.2 |
| Professional services | 0.5 | 0.7 | 0.8 | 0.9 | 0.7 | 0.8 | 0.7 | 0.6 |
| Directors' compensation | 0.2 | 0.2 | 0.3 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 |
| Taxes other than income | 0.0 | 0.5 | 0.2 | 0.5 | 0.1 | 0.6 | 0.4 | 0.0 |
| Intangible asset amortization | 0.2 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 |
| Other operating expenses | 1.5 | 1.6 | 2.0 | 1.2 | 1.2 | 1.6 | 1.7 | 1.9 |
| Total noninterest expenses | 20.7 | 20.3 | 21.2 | 36.4 | 18.8 | 19.4 | 20.3 | 19.0 |
| Income before income tax expense | 12.4 | 11.4 | 11.9 | -6.4 | 10.7 | 10.4 | 8.5 | 8.9 |
| Income tax expense | 2.5 | 2.2 | 2.3 | -1.6 | 1.9 | 2.0 | 1.8 | 1.7 |
| Net income | 9.8 | 9.2 | 9.6 | -4.8 | 8.9 | 8.4 | 6.7 | 7.2 |
| |
| Per share information: | | | | | | | | |
| Basic earnings per share (in usd per share) | $0.95 | $0.88 | $0.92 | ($0.47) | $0.84 | $0.77 | $0.62 | $0.66 |
| Diluted earnings per share (in usd per share) | $0.94 | $0.87 | $0.90 | ($0.47) | $0.83 | $0.76 | $0.60 | $0.65 |
| |
| Dividends paid per share (in usd per share) | $0.20 | $0.20 | $0.19 | $0.19 | $0.19 | $0.19 | $0.19 | $0.19 |