| 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 |
| Net income | 15.7 | 18.6 | 8.3 | 12.7 | 12.4 | 9.5 | 6.4 | 6.9 |
| Depreciation and amortization [+] | 1.3 | 1.4 | 1.3 | 1.0 | 1.0 | 1.3 | 1.0 | 1.0 |
| Depreciation | 1.0 | 1.1 | 1.0 | 0.7 | 0.6 | 0.9 | 1.0 | 0.9 |
| Amortization of intangible assets | 0.4 | 0.3 | 0.3 | 0.3 | 0.4 | 0.4 | 0.0 | 0.0 |
| Stock-based compensation | 0.3 | 0.5 | 0.1 | 0.6 | 0.5 | 0.0 | 0.0 | 0.0 |
| Deferred taxes | -0.3 | -0.4 | -1.3 | 0.3 | -0.2 | -0.8 | -0.1 | 0.6 |
| Change in working capital | 0.2 | 0.7 | -2.1 | 0.3 | -0.2 | -0.3 | 0.0 | -0.2 |
| Other | 0.2 | 0.7 | -2.1 | 0.3 | -0.2 | -0.3 | 0.0 | -0.2 |
| Other operating activities | 1.2 | -5.4 | 8.7 | -1.6 | 0.9 | 4.3 | 0.5 | -1.0 |
| Cash from operations | 18.4 | 15.4 | 15.1 | 13.5 | 14.3 | 13.9 | 7.8 | 7.2 |
| |
| Capital expenditures [+] | -0.9 | -0.6 | -1.1 | -1.9 | -2.1 | -1.2 | -2.2 | -0.5 |
| Purchases of property and equipment | -0.9 | -0.6 | -1.1 | -1.9 | -2.1 | -1.2 | -2.2 | -0.5 |
| Sales of property and equipment | 0.2 | | 0.0 | | | | | |
| Acquisitions | 18.4 | | | | | | | |
| Sales of short-term investments, net [+] | 25.6 | -57.4 | -5.9 | -5.0 | -5.7 | 18.3 | 30.5 | 7.2 |
| Purchases of short-term investments | -32.3 | -68.9 | -24.1 | -35.0 | -13.0 | -3.1 | -1.7 | -21.9 |
| Sales of short-term investments | 57.9 | 11.5 | 18.2 | 30.0 | 7.3 | 21.4 | 32.3 | 29.2 |
| Other cash from investing | -51.9 | 128.9 | -128.4 | 7.1 | -68.7 | -112.3 | -74.3 | -66.2 |
| Cash from investing | -8.7 | 70.9 | -135.3 | 0.3 | -76.5 | -95.3 | -46.0 | -59.4 |
| |
| Cash dividends paid | -5.5 | -4.2 | -3.8 | -3.7 | -3.8 | -3.4 | -2.3 | -2.2 |
| Repurchase of common stock, net | -6.1 | -12.3 | -1.2 | -2.2 | | 15.2 | 11.2 | -6.8 |
| Option exercises | | 0.1 | 0.0 | 0.0 | 0.2 | 0.2 | 0.0 | 0.0 |
| Other cash from financing | -63.8 | -62.6 | 202.6 | -80.6 | 134.3 | 77.1 | 38.0 | 59.3 |
| Cash from financing | -75.4 | -79.2 | 197.5 | -86.6 | 130.3 | 88.7 | 46.9 | 50.4 |
| |
| Free cash flow | 17.5 | 14.8 | 14.0 | 11.6 | 12.2 | 12.7 | 5.6 | 6.7 |
| Per share (diluted) | $2.89 | $2.39 | $2.19 | $1.78 | $1.88 | $4.17 | $2.66 | $3.30 |
| |
| Cash paid for interest | 4.3 | 4.4 | 9.6 | 13.0 | 9.7 | 6.5 | 4.2 | 3.7 |