| 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 |
| Operating Activities: | | | | | | | | |
| Net income | 60.8 | 69.5 | 6.6 | 43.6 | 30.4 | 18.7 | 20.4 | 25.1 |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Depreciation, amortization, and accretion | 10.2 | 1.6 | 4.6 | 2.8 | 9.0 | 8.4 | 8.4 | 6.6 |
| Net change in premises and equipment due to writedown or sale | 0.7 | 0.3 | 0.3 | 0.1 | 0.0 | 0.1 | 0.7 | |
| Share-based compensation | 2.5 | 2.2 | 1.4 | 1.2 | 1.0 | 0.9 | 0.7 | 0.6 |
| Net gain on sale or call of debt securities available for sale | -0.3 | -0.2 | -0.2 | -0.1 | | | | |
| Net change in foreclosed assets due to writedown or sale | 0.0 | 0.2 | 0.1 | 0.3 | | | | |
| Net gain on sale of loans held for sale | -1.8 | -8.1 | -8.9 | -2.3 | -1.7 | -1.8 | -2.5 | -1.8 |
| Origination and participations purchased of loans held for sale | -90.5 | -293.2 | -438.2 | -115.7 | -66.2 | -87.6 | 132.0 | 129.1 |
| Proceeds from sales of loans held for sale | 104.6 | 348.3 | 392.5 | 114.6 | -68.1 | -92.8 | -133.4 | -128.5 |
| Increase in cash surrender value of bank-owned life insurance | -2.3 | -1.9 | -2.1 | -1.9 | -1.6 | 1.4 | -1.4 | -1.3 |
| Decrease (increase) in deferred income taxes, net | 4.3 | 1.8 | -5.2 | 2.7 | -0.7 | 0.7 | -2.9 | 1.3 |
| Change in: | | | | | | | | |
| Other assets | -37.2 | 6.6 | -5.1 | 1.9 | -7.0 | -5.3 | 3.5 | 3.0 |
| Other liabilities | 38.5 | -8.0 | 3.5 | -6.0 | | | 1.3 | |
| Net cash provided by operating activities | 90.3 | 111.6 | 9.2 | 47.3 | 42.8 | 41.1 | 38.2 | 32.7 |
| |
| Investing Activities: | | | | | | | | |
| Purchases of equity securities | -1.3 | | | | -6.5 | -44.0 | -62.2 | -29.2 |
| Proceeds from sales of debt securities available for sale | 129.8 | 52.2 | 27.4 | | | | | |
| Proceeds from maturities and calls of debt securities available for sale | 142.0 | 404.9 | 267.4 | 91.3 | 73.7 | 83.2 | 96.7 | 75.5 |
| Purchases of debt securities available for sale | -386.3 | -1,138.0 | -1,139.7 | -289.7 | -61.5 | -62.8 | -165.6 | -25.4 |
| Net (increase) decrease in loans held for investment | -312.6 | 251.9 | -24.2 | 89.0 | | | -20.6 | -106.3 |
| Purchases of premises and equipment | -2.7 | -2.0 | -2.1 | -2.2 | -5.6 | -5.0 | -5.6 | -14.9 |
| Proceeds from sale of premises and equipment | 0.0 | 0.6 | 0.7 | 0.1 | 0.7 | 0.0 | 2.3 | 1.1 |
| Net cash used in provided by investing activities | -273.3 | -428.3 | -867.4 | 72.7 | -94.4 | -148.8 | -123.6 | 5.0 |
| |
| Financing Activities: | | | | | | | | |
| Deposits | -109.4 | 567.3 | 818.0 | 25.7 | 7.6 | 124.9 | 16.9 | 5.8 |
| Proceeds from issuance of subordinated debt | | | 65.0 | | | | | |
| Redemption of subordinated debentures | | -10.8 | | | | | | -12.7 |
| Payments on finance lease liability | -0.2 | -0.1 | -0.1 | -0.1 | | | | |
| Payments of Federal Home Loan Bank borrowings | -31.0 | -43.0 | -54.4 | -58.0 | -89.0 | | | |
| Proceeds from other long-term debt | 25.0 | | | 35.0 | | | | 25.0 |
| Payments of other long-term debt | -10.0 | -10.8 | -32.3 | -10.3 | -5.0 | | -5.0 | -15.2 |
| Taxes paid relating to the release/lapse of restriction on RSUs | -0.3 | -0.1 | -0.1 | -0.1 | -0.1 | -0.1 | | |
| Dividends paid | -14.9 | -14.3 | -14.2 | -11.5 | -9.5 | -8.1 | -7.3 | -6.3 |
| Repurchase of common stock | -2.7 | -11.6 | -4.6 | -4.7 | -2.1 | | | |
| Net cash provided by financing activities | 65.5 | 437.9 | 867.5 | -92.1 | 46.2 | 115.4 | 81.5 | -14.0 |
| Net change in cash and cash equivalents | -117.4 | 121.2 | 9.2 | | | | | |
| |
| Supplemental disclosures of cash flow information: | | | | | | | | |
| Cash paid during the period for interest | 27.8 | 21.5 | 31.6 | 34.1 | 22.4 | 15.2 | 12.8 | 10.0 |
| Cash paid during the period for income taxes | 13.2 | 18.0 | 10.5 | 7.3 | 6.2 | 13.2 | 8.0 | 7.7 |
| Supplemental schedule of non-cash investing and financing activities: | | | | | | | | |
| Transfer of loans to foreclosed assets | 0.5 | 0.3 | 1.6 | | | | | |
| Investment securities purchased but not settled | | 2.5 | 2.3 | | | | | |
| Transfer of premises and equipment to assets held for sale | 1.3 | | 1.3 | 0.6 | | | | |
| Transfer due to adoption of ASU 2016-03, reclassified from Retained Earnings to Allowance for Credit Losses | | | 5.4 | | | | | |
| Supplemental Schedule of non-cash investing activities from acquisition: | | | | | | | | |
| Non-cash assets acquired: | | | | | | | | |
| Other assets | | | | | | | | |
| Total non-cash assets acquired | | | | | | | | |
| Liabilities assumed: | | | | | | | | |
| Deposits | | | | | | | | |
| Short-term borrowings | | | | | 34.2 | | | |
| Total liabilities assumed | | | | | | | | |