| 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 |
| | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F | 20-F |
| Net income | 119.1 | 57.4 | -134.2 | -16.3 | 10.8 | -517.5 | -170.0 | -70.5 |
| Depreciation and amortization | 43.3 | 40.5 | 43.0 | 48.9 | 52.2 | 87.0 | 81.6 | 76.3 |
| Asset impairment charges | | | | 14.0 | | 442.3 | | |
| Stock-based compensation | | | | 7.6 | 7.3 | 8.2 | 8.3 | 8.3 |
| Change in working capital [+] | 3.9 | 2.6 | -3.4 | -10.8 | 9.8 | 7.7 | -1.7 | 2.5 |
| Accounts receivable | | | | -4.9 | 2.0 | 1.0 | -1.4 | 1.9 |
| Inventories | | | | 0.3 | -0.1 | 0.1 | 0.4 | 1.1 |
| Accounts payable | 1.5 | 1.2 | -2.8 | 0.3 | 3.1 | 1.4 | -2.4 | -0.7 |
| Deferred revenues | 2.0 | 2.9 | 0.3 | -1.6 | 0.9 | 2.4 | -1.6 | -1.0 |
| Other | 0.5 | -1.5 | -0.8 | -4.9 | 3.8 | 2.9 | 3.3 | 1.3 |
| Other operating activities | -7.5 | -10.7 | 111.8 | 6.5 | -0.1 | -4.4 | 60.8 | 7.3 |
| Cash from operations | 158.9 | 89.7 | 17.2 | 49.9 | 79.9 | 23.4 | -21.0 | 23.9 |
| |
| Capital expenditures [+] | 231.6 | 20.6 | 6.1 | -2.9 | -2.6 | -125.9 | -51.1 | -155.6 |
| Purchases of property and equipment | 231.0 | 19.0 | 6.0 | -2.8 | -2.6 | -125.9 | -51.1 | -155.6 |
| Capitalized product costs | 0.7 | 1.6 | 0.1 | -0.1 | | | | |
| Sales of property and equipment | 4.4 | 33.7 | 15.6 | 41.3 | 14.6 | 2.0 | | |
| Other cash from investing | -509.1 | -41.0 | -11.3 | | 87.4 | -28.5 | 9.5 | -0.1 |
| Cash from investing | -273.1 | 13.4 | 10.5 | 38.4 | 99.4 | -152.3 | -41.6 | -155.6 |
| |
| Cash dividends paid | 79.8 | 8.8 | | | | | | |
| Issuance of common stock, net | 9.1 | 45.4 | 12.0 | -48.7 | -15.2 | 77.3 | | -2.7 |
| Financing costs | | | | -0.4 | -2.8 | 0.0 | -0.5 | -5.5 |
| Other cash from financing | -4.0 | -113.4 | -85.1 | -63.0 | -81.4 | -3.8 | -9.9 | 103.2 |
| Cash from financing | 84.9 | -59.2 | -73.1 | -111.4 | -93.7 | 73.6 | -9.5 | 106.0 |
| |
| Free cash flow | 389.8 | 108.7 | 23.2 | 47.1 | 77.4 | -102.5 | -72.1 | -131.6 |
| Per share (diluted) | $4.69 | $1.30 | $0.27 | $0.49 | $0.74 | ($1.07) | ($0.90) | ($1.66) |
| |
| Cash paid for interest | 21.3 | 19.6 | 21.4 | 28.6 | 25.7 | 24.5 | 19.3 | 13.0 |