| 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 | 27.3 | 21.0 | 56.4 | -5.3 | -130.0 | 241.8 | -45.8 | -35.5 |
| Depreciation and amortization [+] | 131.3 | 77.5 | 41.0 | 38.3 | 46.2 | 43.5 | 46.4 | 52.2 |
| Depreciation | 131.3 | 77.5 | 41.0 | 38.3 | 46.2 | 23.9 | 22.3 | 18.9 |
| Amortization of intangible assets | | | | | | 19.6 | 24.2 | 33.4 |
| Asset impairment charges | 122.2 | 16.2 | | 8.6 | 87.2 | 4.4 | 48.5 | |
| Stock-based compensation | 33.2 | 75.0 | | 31.0 | 18.4 | 24.4 | 21.0 | 17.8 |
| Deferred taxes | -18.3 | -3.8 | -5.5 | 4.8 | 21.6 | -173.0 | -10.0 | -0.1 |
| Change in working capital [+] | 70.7 | 64.8 | 0.0 | -4.2 | 48.7 | -132.1 | -25.4 | -19.3 |
| Accounts receivable | 37.8 | -30.8 | -26.8 | -37.8 | 31.3 | -50.0 | -16.8 | -4.8 |
| Inventories | | | | | | | -13.0 | 3.9 |
| Other current assets | 1.2 | 4.0 | -10.5 | 3.5 | -17.2 | 6.6 | -13.6 | 1.6 |
| Accounts payable | 98.9 | -46.4 | 5.6 | | | | | |
| Deferred revenues | -27.1 | 76.0 | 7.4 | 32.9 | -14.9 | 14.5 | 11.4 | -23.5 |
| Other | -40.0 | 62.0 | 24.2 | -2.8 | 49.5 | -103.2 | 6.6 | 3.6 |
| Other operating activities | -18.7 | -50.0 | 46.2 | 13.2 | -74.9 | 62.8 | -80.6 | 147.6 |
| Cash from operations | 347.6 | 200.9 | 138.1 | 86.5 | 17.3 | 71.8 | -45.9 | 162.7 |
| |
| Capital expenditures [+] | -22.7 | -8.8 | -4.7 | -18.6 | -20.3 | -33.0 | -29.4 | -23.6 |
| Purchases of property and equipment | -22.7 | -8.8 | -4.7 | -18.6 | -20.3 | -33.0 | -29.4 | -23.6 |
| Sales of property and equipment | | 37.2 | | 23.1 | 2.1 | 10.6 | 0.7 | 8.6 |
| Acquisitions | -74.2 | 150.3 | -14.7 | -4.8 | -32.7 | | -88.2 | -158.8 |
| Other cash from investing | -19.4 | -14.8 | -9.6 | 0.5 | 0.5 | 1.4 | 91.8 | 143.9 |
| Cash from investing | -116.3 | 164.0 | -29.0 | 0.1 | -50.4 | -20.9 | -25.2 | -29.9 |
| |
| Cash dividends paid | | | | | | -0.3 | -32.9 | -42.3 |
| Repurchase of common stock, net | -32.8 | 0.8 | | | | -1.8 | -3.4 | -2.4 |
| Financing costs | | -15.1 | -3.1 | | | | -21.6 | |
| Other cash from financing | -153.9 | -289.3 | -83.2 | -11.7 | 21.4 | -30.6 | 50.4 | -143.9 |
| Cash from financing | -186.7 | -273.4 | -80.1 | -11.7 | 21.4 | -32.6 | 35.7 | -188.6 |
| |
| Free cash flow | 324.9 | 192.1 | 133.4 | 67.9 | -3.0 | 38.8 | -75.3 | 139.2 |
| Per share (diluted) | $1.10 | $2.12 | $1.84 | $0.98 | ($0.05) | $0.70 | ($1.47) | $2.79 |