| 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 |
| Net income | 87.8 | 64.9 | 75.7 | 78.3 | 77.9 | 42.0 | 39.1 | 32.0 |
| Depreciation and amortization | 14.2 | 12.6 | 9.1 | 6.9 | 6.7 | 8.4 | 9.2 | 8.3 |
| Stock-based compensation | 7.2 | 6.8 | 6.3 | 5.5 | 6.0 | 6.4 | 6.1 | 4.0 |
| Tax benefit from stock-based compensation | | | | | 0.6 | 0.4 | | |
| Deferred taxes | -1.5 | 1.7 | 1.4 | 1.6 | -0.9 | -1.9 | -0.9 | -1.1 |
| Change in working capital [+] | -30.1 | -4.7 | -8.1 | 0.1 | 12.8 | -2.7 | -2.2 | -7.7 |
| Accounts receivable | -71.1 | -4.8 | 22.2 | -21.8 | -2.5 | -23.2 | -4.6 | -2.8 |
| Other current assets | -10.7 | 0.8 | -0.9 | 2.2 | -2.4 | -1.1 | 0.1 | -0.9 |
| Accounts payable | 18.7 | 3.6 | -28.8 | 15.7 | 12.1 | 19.7 | 2.3 | -4.5 |
| Accrued expenses | 35.1 | 1.8 | -2.4 | 2.3 | 2.1 | 1.2 | -3.5 | -0.6 |
| Other | -2.1 | -6.1 | 1.8 | 1.8 | 3.5 | 0.6 | 3.5 | 1.1 |
| Other operating activities | -14.8 | -9.2 | -14.7 | -27.6 | -21.9 | 0.4 | 0.0 | 5.2 |
| Cash from operations | 62.8 | 72.1 | 69.8 | 64.8 | 81.2 | 53.0 | 51.3 | 40.9 |
| |
| Capital expenditures [+] | -11.8 | -12.9 | -14.0 | -8.3 | -8.2 | -5.4 | -6.9 | -8.2 |
| Purchases of property and equipment | -3.4 | -4.3 | -5.4 | -4.8 | -5.6 | -4.5 | -5.4 | -6.7 |
| Capitalized product costs | -8.5 | -8.7 | -8.6 | -3.6 | -2.6 | -1.0 | -1.5 | -1.5 |
| Sales of property and equipment | | | | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Purchases of intangible assets | | -3.5 | -3.6 | | | | | |
| Acquisitions | | -10.0 | | | | | | |
| Cash from investing | -11.8 | -26.4 | -17.5 | -8.3 | -8.2 | -5.4 | -6.9 | -8.2 |
| |
| Cash dividends paid | -24.4 | -21.6 | -21.5 | -21.4 | -43.3 | | -33.0 | |
| Repurchase of common stock, net | -3.9 | | | | | | | |
| Option exercises | 1.5 | 1.4 | 1.4 | 1.3 | 1.1 | 1.1 | 1.1 | 0.9 |
| Other cash from financing | 1.0 | 0.1 | 1.5 | 0.0 | 0.1 | -36.0 | 3.4 | -19.9 |
| Cash from financing | -28.9 | -23.0 | -21.4 | -22.7 | -44.3 | -37.2 | -30.7 | -20.8 |
| |
| Free cash flow | 59.5 | 67.8 | 64.4 | 60.1 | 75.5 | 48.6 | 45.9 | 34.1 |
| Per share (diluted) | $0.76 | $0.88 | $0.84 | $0.85 | $1.11 | $0.72 | $0.68 | $0.50 |
| |
| Cash paid for income taxes | 19.6 | 16.0 | 13.7 | 21.3 | 19.8 | | | |