| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | 91.9 | 71.8 | 20.1 | 54.7 | 16.7 | 32.6 | 19.6 | 22.0 |
| Depreciation and amortization | 48.8 | 41.4 | 49.9 | 45.7 | 35.5 | 19.9 | 14.8 | 7.9 |
| Asset impairment charges | | | | | | | | 0.4 |
| Stock-based compensation | 36.2 | 28.3 | 22.8 | 23.9 | 25.0 | 28.1 | 28.9 | 23.8 |
| Tax benefit from stock-based compensation | | | | | | | | -13.1 |
| Deferred taxes | -1.8 | 1.0 | -2.0 | -6.3 | 12.5 | 1.8 | -4.8 | -4.9 |
| Change in working capital [+] | 17.2 | 18.9 | 6.4 | 9.1 | -4.7 | 10.9 | 18.0 | 43.0 |
| Accounts receivable | -4.1 | 0.5 | -6.2 | 2.6 | -10.0 | -13.2 | -11.1 | -10.1 |
| Other current assets | -13.2 | 9.8 | 4.2 | 0.1 | -6.7 | -2.4 | 3.4 | 20.5 |
| Deferred revenues | | | | | | 25.0 | 22.6 | 22.6 |
| Income taxes | | | | | | | | 0.1 |
| Other | 34.4 | 8.6 | 8.4 | 6.4 | 12.0 | 1.6 | 3.1 | 10.0 |
| Other operating activities | 24.1 | 3.7 | 5.4 | -24.9 | | | | 3.8 |
| Cash from operations | 216.4 | 165.1 | 102.6 | 102.2 | 108.0 | 100.7 | 87.0 | 82.9 |
| |
| Capital expenditures [+] | -68.6 | -30.5 | -29.4 | -38.7 | -58.0 | -48.0 | -17.0 | -18.7 |
| Purchases of property and equipment | -28.1 | -25.6 | -26.1 | -34.9 | -55.1 | -40.0 | -14.0 | -18.0 |
| Capitalized product costs | -40.5 | -4.8 | -3.3 | -3.8 | -3.0 | -8.0 | -3.0 | -0.7 |
| Acquisitions | -181.6 | | | -0.8 | -49.6 | | -62.4 | -10.1 |
| Other cash from investing | -0.2 | -4.9 | 2.2 | 26.7 | 50.2 | -8.4 | 7.5 | -0.3 |
| Cash from investing | -250.4 | -35.3 | -27.2 | -12.8 | -57.4 | -56.4 | -71.8 | -29.0 |
| |
| Cash dividends paid | -30.7 | -24.4 | | -104.9 | | | | |
| Repurchase of common stock, net | -26.5 | 23.2 | | | -25.0 | -60.2 | -14.8 | |
| Option exercises | 2.1 | 1.2 | 5.4 | 2.5 | 1.7 | 8.7 | 7.2 | 9.7 |
| Other cash from financing | -18.4 | -2.2 | 3.7 | -2.4 | -7.2 | 15.8 | 16.3 | 34.6 |
| Cash from financing | -77.7 | -4.6 | -1.7 | -109.7 | -33.9 | -53.1 | -5.7 | 24.9 |
| |
| Free cash flow | 188.2 | 139.4 | 76.6 | 67.3 | 53.0 | 60.8 | 73.0 | 64.9 |
| Per share (diluted) | $3.96 | $3.70 | $2.06 | $1.79 | $1.42 | $1.47 | $1.93 | $1.79 |
| |
| Cash paid for income taxes | 19.1 | 8.8 | 1.9 | 0.6 | 5.0 | 19.2 | 14.5 | 0.3 |