| 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 | 99.4 | 42.8 | -15.0 | 117.7 | 88.0 | 33.1 | 21.5 | 18.5 |
| Depreciation and amortization | 124.0 | 62.8 | 53.8 | 44.3 | 35.3 | 31.8 | 31.5 | 32.2 |
| Stock-based compensation | 8.1 | 8.8 | 4.8 | 4.8 | 5.5 | 2.5 | 1.7 | 4.9 |
| Deferred taxes | 48.6 | 1.5 | 7.2 | 21.6 | 23.9 | 372.4 | 15.6 | 6.1 |
| Change in working capital [+] | -46.0 | 28.7 | -19.1 | -9.9 | -0.5 | -23.2 | -13.8 | 1.5 |
| Accounts receivable | -19.2 | -10.8 | 23.6 | -0.9 | -1.9 | -10.5 | -7.8 | -0.4 |
| Inventories | -4.1 | -0.7 | 0.4 | 4.2 | -2.4 | -0.9 | 2.8 | -1.5 |
| Other current assets | -5.2 | 8.3 | -2.7 | -3.2 | 5.8 | -3.0 | -7.9 | -5.7 |
| Deferred revenues | 9.4 | 2.3 | -2.8 | 11.5 | 9.6 | 1.3 | -0.7 | 3.0 |
| Income taxes | -1.7 | 2.2 | -4.5 | 6.2 | 0.2 | -3.0 | -6.0 | 0.1 |
| Other | -25.3 | 27.4 | -33.2 | -27.8 | -11.8 | -7.1 | 5.8 | 6.1 |
| Other operating activities | 6.1 | 44.6 | -0.6 | 25.7 | 32.3 | -285.6 | 52.3 | 18.5 |
| Cash from operations | 240.2 | 189.3 | 31.1 | 204.3 | 184.4 | 131.0 | 108.8 | 81.7 |
| |
| Capital expenditures [+] | -100.1 | -54.1 | -52.6 | -57.9 | -40.9 | -37.7 | -15.4 | -19.5 |
| Purchases of property and equipment | -100.1 | -54.1 | -52.6 | -57.9 | -40.9 | -37.7 | -15.4 | -19.5 |
| Sales of property and equipment | 0.1 | 0.0 | 0.3 | 0.1 | 0.2 | 0.7 | 0.7 | 0.3 |
| Purchases of intangible assets | | | | -0.3 | | | | |
| Acquisitions | -424.9 | -1.9 | | -52.6 | -45.8 | | | |
| Other cash from investing | 18.4 | -35.0 | | | | | | |
| Cash from investing | -506.6 | -90.9 | -52.3 | -110.7 | -86.4 | -37.0 | -14.7 | -19.2 |
| |
| Cash dividends paid | -4.6 | -0.8 | -1.8 | -7.4 | -8.3 | -11.4 | -201.1 | -36.5 |
| Repurchase of common stock, net | 0.9 | 8.2 | 2.6 | -455.3 | -341.2 | 0.5 | 0.1 | 156.9 |
| Financing costs | -16.2 | | | -10.6 | -27.1 | -1.3 | -5.2 | -1.7 |
| Other cash from financing | 123.3 | -17.7 | 57.1 | 516.5 | 432.3 | -12.1 | 110.6 | -196.4 |
| Cash from financing | 135.7 | -10.2 | 57.9 | 64.3 | 109.9 | -21.7 | -85.2 | -74.2 |
| |
| Free cash flow | 140.2 | 135.2 | -21.4 | 146.4 | 143.5 | 93.3 | 93.4 | 62.2 |
| Per share (diluted) | $1.66 | $1.61 | ($0.27) | $1.75 | $1.64 | $1.18 | $2.16 | $1.72 |
| |
| Cash paid for interest | 81.0 | 74.9 | 75.6 | 53.7 | 38.6 | 31.4 | 24.3 | 23.2 |
| Cash paid for income taxes | 3.6 | 1.8 | -2.2 | 10.0 | 5.0 | | | |