| In millions, except per share items | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Interest and dividend income: | | | | | | | | |
| Loans | 249.0 | 281.6 | 262.5 | 229.0 | 201.3 | 192.2 | 191.7 | 191.6 |
| Taxable investment securities | 3.4 | 4.1 | 6.0 | 6.4 | 6.2 | 4.4 | 3.2 | 2.1 |
| Non-taxable investment securities | 8.0 | 7.7 | 7.1 | 6.6 | 5.8 | 4.8 | 3.7 | 3.1 |
| Short-term investments and other | 3.0 | 4.3 | 5.2 | 3.3 | 1.9 | 1.4 | 1.4 | 1.0 |
| Total interest and dividend income | 273.7 | 308.4 | 292.9 | 258.7 | 227.6 | 213.7 | 206.8 | 203.2 |
| |
| Interest expense: | | | | | | | | |
| Deposits | 32.0 | 59.1 | 39.8 | 20.9 | 16.6 | 16.0 | 14.1 | 13.4 |
| Federal Home Loan Bank borrowings | 5.5 | 15.0 | 13.8 | 9.9 | 8.0 | 8.0 | 9.1 | 11.0 |
| Junior subordinated debentures | 2.7 | 4.2 | 3.9 | 2.9 | 2.4 | 3.9 | 3.9 | 4.4 |
| Repurchase agreements and other short-term borrowings | 0.1 | 2.1 | 0.8 | 0.3 | 0.2 | 0.1 | 0.1 | 0.4 |
| Total interest expense | 40.3 | 80.4 | 58.3 | 34.0 | 27.2 | 27.9 | 27.1 | 29.2 |
| Net interest income | 233.4 | 228.1 | 234.6 | 224.7 | 200.4 | 185.8 | 179.7 | 174.0 |
| |
| Provision/(credit) for loan losses | | | | | | | | |
| Net interest income after provision/(credit) for loan losses | 201.4 | 231.6 | 236.8 | 232.4 | 207.4 | 187.3 | 186.1 | 184.0 |
| |
| Fees and other income: | | | | | | | | |
| Fees | 327.3 | 329.6 | 384.6 | 386.3 | 366.2 | 348.5 | 326.9 | 320.4 |
| Fees growth | -0.7% | -14.3% | -0.5% | 5.5% | 5.1% | 6.6% | 2.0% | 6.2% |
| Other | 2.2 | 3.0 | 0.9 | 2.1 | 3.4 | 3.7 | 0.9 | 2.4 |
| Total fees and other income | 93.9 | 101.5 | 150.0 | 154.0 | 158.8 | 161.2 | 140.8 | 136.3 |
| |
| Operating expense: | | | | | | | | |
| Salaries and employee benefits | 139.7 | 134.3 | 161.5 | 178.5 | 164.7 | 159.4 | 146.6 | 140.8 |
| Occupancy and equipment | 31.1 | 32.0 | 32.1 | 30.2 | 28.0 | 27.9 | 31.0 | 29.8 |
| Information systems | 29.6 | 22.6 | 25.2 | 21.8 | 19.2 | 17.0 | 5.8 | 5.8 |
| Professional services | 13.8 | 15.2 | 13.2 | 13.8 | 11.6 | 12.9 | 12.5 | 12.1 |
| Merger costs | | | | | | | | |
| Marketing and business development | 6.3 | 6.4 | 7.6 | 7.8 | 7.6 | 9.1 | 8.0 | 7.1 |
| Amortization of intangibles | 2.7 | 2.7 | 2.9 | 5.6 | 6.3 | 6.7 | 4.8 | 4.3 |
| FDIC insurance | 2.6 | 1.3 | 2.9 | 3.0 | 3.5 | 4.0 | 3.5 | 3.7 |
| Restructuring | | 1.6 | 7.8 | | 2.0 | 3.7 | 0.7 | |
| Other | 15.5 | 13.9 | 14.2 | 14.5 | 12.5 | 14.6 | 14.1 | 17.1 |
| Total operating expense | 241.3 | 230.2 | 267.4 | 299.9 | 265.0 | 255.2 | 227.1 | 220.7 |
| Income/(loss) before income taxes | 45.2 | 80.4 | 83.9 | 45.1 | 75.8 | 69.3 | 73.6 | 74.5 |
| Income tax expense | 8.9 | 22.6 | 37.5 | 46.2 | 31.0 | 30.4 | 32.4 | 33.0 |
| Net income/(loss) before attribution to noncontrolling interests | 45.2 | 80.4 | 83.9 | 45.1 | 75.8 | 69.3 | 73.6 | 74.5 |
| Less: Net income attributable to noncontrolling interests | 0.0 | -0.4 | -3.5 | -4.5 | -4.2 | -4.4 | -4.8 | -3.9 |
| Net income attributable to the Company | 45.2 | 80.0 | 80.4 | 40.6 | 71.6 | 64.9 | 68.8 | 70.5 |
| |
| Adjustments to net income attributable to the Company to arrive at net income attributable to common shareholders | | | | | | | | |
| Net income attributable to common shareholders, treasury stock method | 45.6 | 81.2 | 78.7 | 35.7 | 67.6 | 61.9 | 64.8 | 53.9 |
| |
| Basic earnings per share attributable to common shareholders: | | | | | | | | |
| Total attributable to common shareholders (in dollars per share) | $0.55 | $0.97 | $0.94 | $0.43 | $0.83 | $0.77 | $0.82 | $0.70 |
| |
| Weighted average basic common shares outstanding (in shares) | 82.4 | 83.4 | 83.6 | 82.4 | 81.3 | 80.9 | 79.0 | 77.0 |
| |
| Diluted earnings per share attributable to common shareholders: | | | | | | | | |
| Total attributable to common shareholders (in dollars per share) | $0.55 | $0.97 | $0.92 | $0.42 | $0.81 | $0.74 | $0.80 | $0.68 |
| Weighted average diluted common shares outstanding (in shares) | 82.8 | 83.9 | 85.3 | 84.8 | 83.2 | 83.4 | 81.0 | 79.3 |