| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Interest income | | | | | | | | |
| Interest and fees on loans | 287.5 | 252.1 | 285.0 | 304.2 | 251.2 | 202.6 | 147.8 | 100.4 |
| |
| Interest and dividends on investment securities: | | | | | | | | |
| Taxable interest income | 66.1 | 41.8 | 35.4 | 41.1 | 27.6 | 16.4 | 14.0 | 14.3 |
| Non-taxable interest income | 3.3 | 3.8 | 4.6 | 4.6 | 4.7 | 3.9 | 3.1 | 3.3 |
| Total interest income | 360.0 | 298.8 | 326.6 | 356.2 | 286.0 | 224.3 | 164.9 | 118.0 |
| |
| Interest expense | | | | | | | | |
| Deposits | 16.1 | 12.6 | 30.7 | 55.1 | 32.6 | 12.9 | 7.1 | 4.8 |
| Federal funds purchased and securities sold under agreements to repurchase | 1.5 | 0.2 | 0.7 | 2.3 | 1.6 | 1.0 | 0.4 | 0.2 |
| Short-term borrowings | 1.6 | 0.3 | 0.2 | 1.0 | 1.5 | 1.1 | 0.6 | 0.0 |
| Long-term debt | 1.3 | 0.7 | 0.5 | 2.6 | 0.9 | 0.6 | 0.2 | 0.0 |
| Subordinated notes | 12.3 | 9.9 | 7.0 | 2.9 | 3.1 | 1.9 | 1.9 | 1.2 |
| Junior subordinated debt owed to unconsolidated trusts | 12.3 | 9.9 | 7.0 | 2.9 | 3.1 | 1.9 | 1.9 | 1.2 |
| Total interest expense | 36.5 | 28.1 | 43.7 | 69.0 | 44.6 | 20.9 | 10.2 | 6.2 |
| Net interest income | 323.4 | 270.7 | 282.9 | 287.2 | 241.4 | 203.4 | 154.7 | 111.8 |
| |
| Provision for credit losses | | | | | | | | |
| Net interest income after provision for credit losses | 318.8 | 285.8 | 244.1 | 276.8 | 237.0 | 198.1 | 149.1 | 110.2 |
| |
| Noninterest income | | | | | | | | |
| Noninterest income | | | | | | | | |
| Mortgage revenue | 1.9 | 7.2 | 13.0 | | | | | |
| Unrealized net gains (losses) recognized on equity securities | -2.2 | 3.0 | -0.4 | | | | | |
| Other income | 14.8 | 10.3 | 8.4 | 8.0 | 6.2 | 5.3 | 4.3 | 3.6 |
| |
| Noninterest expense | | | | | | | | |
| Data processing | 21.6 | 21.9 | 16.4 | 21.5 | 16.4 | 16.7 | 18.2 | 12.9 |
| Net occupancy expense of premises | 19.1 | 18.3 | 17.6 | 18.2 | 14.8 | 13.8 | 11.6 | 8.7 |
| Furniture and equipment expenses | 7.6 | 8.3 | 9.6 | 9.5 | 7.2 | 7.1 | 6.6 | 5.0 |
| Amortization of intangible assets | 11.6 | 11.3 | 10.0 | 9.5 | 5.9 | 5.2 | 4.4 | 3.2 |
| Other expense | 52.4 | 43.3 | 40.7 | 44.3 | 31.9 | 29.1 | 28.6 | 19.6 |
| Total noninterest expense | 283.9 | 261.8 | 234.2 | 258.8 | 193.0 | 174.4 | 147.9 | 115.3 |
| Income before income taxes | 161.7 | 156.8 | 128.2 | 134.4 | 133.9 | 108.1 | 76.4 | 59.7 |
| Income taxes | 33.4 | 33.4 | 27.9 | 31.5 | 35.0 | 45.4 | 26.7 | 20.7 |
| Net income | 128.3 | 123.4 | 100.3 | 103.0 | 98.9 | 62.7 | 49.7 | 39.0 |
| |
| Basic earnings per common share (in dollars per share) | $2.32 | $2.23 | $1.84 | $1.88 | $2.02 | $1.47 | $1.42 | $1.32 |
| Diluted earnings per common share (in dollars per share) | $2.29 | $2.20 | $1.83 | $1.87 | $2.01 | $1.45 | $1.40 | $1.32 |
| |
| Dividends declared per share of common stock (in dollars per share) | $0.92 | $0.92 | $0.88 | $0.84 | $0.80 | $0.72 | | |