| In millions, except per share items | Jun-30-16 | Mar-31-16 | Dec-31-15 | Sep-30-15 | Jun-30-15 | Mar-31-15 | Dec-31-14 | Sep-30-14 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Interest Income | | | | | | | | |
| Interest and fees on loans | 67.6 | 66.0 | 64.9 | 64.1 | 62.6 | 61.0 | 59.2 | 58.0 |
| Interest and dividends on investment securities | 12.8 | 12.9 | 12.9 | 12.8 | 13.0 | 13.6 | 14.1 | 14.6 |
| Other interest income | 1.0 | 0.9 | 0.8 | 0.8 | 0.7 | 0.6 | 0.6 | 0.9 |
| Total interest income | 81.4 | 79.8 | 78.6 | 77.7 | 76.3 | 75.2 | 73.9 | 73.5 |
| |
| Interest Expense | | | | | | | | |
| Deposits | 7.3 | 7.2 | 7.1 | 6.9 | 6.9 | 6.9 | 6.9 | 7.0 |
| Retail repurchase agreements | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Federal Home Loan Bank advances | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 2.0 | 1.8 |
| Other borrowed funds | 1.2 | 1.2 | 1.1 | 1.1 | 1.2 | 1.2 | 1.1 | 1.1 |
| Total interest expense | 10.5 | 10.4 | 10.2 | 10.1 | 10.1 | 10.1 | 10.1 | 10.0 |
| Net Interest Income before Provision for (Recovery of Provision for) Loan Losses | 70.9 | 69.4 | 68.4 | 67.6 | 66.2 | 65.1 | 63.8 | 63.5 |
| Provision for (Recovery of provision for) loan losses | -1.1 | -2.4 | -3.0 | -3.3 | -4.9 | -5.8 | -5.4 | -2.2 |
| Net Interest Income after Provision for (Recovery of Provision for) Loan Losses | 71.9 | 71.8 | 71.4 | 70.9 | 71.1 | 70.9 | 69.1 | 65.7 |
| |
| Noninterest Income | | | | | | | | |
| Service charges on deposit accounts | 6.6 | 6.5 | 6.3 | 6.2 | 6.0 | 6.2 | 6.4 | 6.6 |
| Mortgage loan income | 3.6 | 3.3 | 1.6 | 1.4 | 1.2 | 1.2 | 0.9 | 0.9 |
| Cardholder and merchant services income | 5.2 | 5.1 | 5.0 | 4.9 | 4.8 | 4.8 | 4.8 | 4.6 |
| Trust and investment services | 1.5 | 1.6 | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.4 |
| Bank-owned life insurance | 1.2 | 1.2 | 1.2 | 1.2 | 1.1 | 1.2 | 1.2 | 1.1 |
| Other service charges, commissions and fees | 1.9 | 1.8 | 1.8 | 1.6 | 1.5 | 1.4 | 1.3 | 1.3 |
| Other income | 1.4 | 1.1 | 0.8 | 0.6 | 0.3 | 0.3 | 0.4 | 0.3 |
| Total noninterest income | 21.5 | 20.5 | 18.2 | 17.7 | 16.7 | 17.5 | 17.4 | 17.0 |
| |
| Noninterest Expense | | | | | | | | |
| Personnel expense | 42.8 | 43.4 | 43.8 | 41.8 | 44.4 | 43.9 | 43.7 | 42.5 |
| Net occupancy expense | 5.9 | 5.8 | 5.7 | 5.8 | 5.7 | 6.0 | 6.1 | 5.9 |
| Furniture, equipment and data processing expense | 8.2 | 8.1 | 8.0 | 8.1 | 8.2 | 8.3 | 8.3 | 8.4 |
| Professional fees | 2.1 | 2.0 | 2.1 | 2.3 | 2.4 | 2.4 | 2.5 | 2.4 |
| Stationery, printing and supplies | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.7 | 0.6 | 0.6 |
| Advertising and marketing | 0.3 | 0.4 | 0.5 | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 |
| Other real estate owned expense | 2.0 | 2.4 | 2.3 | 2.0 | 1.4 | 1.9 | 1.8 | 1.2 |
| Credit/debit card expense | 1.9 | 1.9 | 2.0 | 2.2 | 2.1 | 2.2 | 2.3 | 2.3 |
| FDIC insurance | 1.7 | 1.8 | 1.7 | 1.7 | 1.7 | 1.9 | 2.1 | 2.3 |
| Loan collection expense | 0.3 | 0.5 | 0.7 | 0.7 | 1.0 | 1.2 | 1.6 | 2.0 |
| Merger-related expense | 1.0 | 0.8 | | | | | | |
| Core deposit premium intangible amortization | 1.3 | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 | 1.4 |
| Other expense | 4.8 | 4.8 | 4.5 | 6.4 | 6.6 | 7.1 | 7.5 | 6.0 |
| Total noninterest expense | 74.8 | 75.9 | 75.5 | 73.7 | 76.3 | 77.7 | 78.5 | 75.6 |
| Income before income taxes | 18.6 | 16.3 | 14.0 | 15.0 | 11.5 | 10.6 | 8.0 | 7.1 |
| Income tax expense | 8.9 | 8.0 | 7.1 | -136.2 | -139.9 | -141.1 | -142.5 | -1.1 |
| Tax rate | 47.9% | 49.2% | 50.7% | -910.1% | -1214.8% | -1330.7% | | |
| Net income | 9.7 | 8.3 | 6.9 | 151.2 | 151.4 | 151.7 | 150.5 | 8.1 |
| |
| Weighted average number of shares outstanding - basic (shares) | 24.3 | 24.2 | 24.2 | 23.6 | 23.0 | 22.4 | 21.9 | 21.8 |
| Weighted average number of shares outstanding - diluted (shares) | 24.3 | 24.3 | 24.2 | 23.6 | 23.0 | 22.4 | 21.9 | 21.8 |
| |
| Net income per share - basic and diluted (in dollars per share) | $0.40 | $0.34 | $0.28 | $6.87 | $6.89 | $6.92 | $6.88 | $0.37 |