| 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 | 18.1 | -3.8 | -6.2 | -59.9 | 7.6 | 33.1 | 12.5 | 20.1 |
| Depreciation and amortization | 46.9 | 40.0 | 39.6 | 48.6 | 44.2 | 38.5 | 35.6 | 43.9 |
| Asset impairment charges | | 1.6 | 1.8 | 77.9 | 0.8 | | 16.6 | |
| Stock-based compensation | 1.3 | 1.0 | 1.2 | 1.8 | 3.2 | 7.3 | 2.5 | 3.1 |
| Tax benefit from stock-based compensation | | | | | | | -1.1 | -1.0 |
| Deferred taxes | 1.8 | 0.0 | -2.1 | -21.8 | -2.3 | -16.4 | -3.9 | 7.5 |
| Change in working capital [+] | 11.2 | 26.4 | 12.4 | -8.7 | -7.8 | -7.4 | -12.4 | 13.7 |
| Accounts receivable | -16.3 | 0.8 | 11.2 | -7.3 | -1.7 | 5.5 | -5.6 | 10.6 |
| Inventories | -25.9 | 17.0 | 2.9 | -8.6 | -7.7 | -2.7 | 4.8 | 4.8 |
| Other current assets | 0.7 | -0.4 | -3.0 | 2.6 | 0.4 | -1.4 | -3.1 | -0.9 |
| Deferred revenues | 35.5 | | | | | | | |
| Income taxes | -1.0 | 3.4 | 2.8 | 1.0 | 0.3 | -3.2 | 5.3 | 0.4 |
| Other | 18.1 | 5.6 | -1.4 | 3.6 | 0.8 | -5.6 | -13.8 | -1.3 |
| Other operating activities | -25.0 | -17.3 | 5.8 | 0.3 | 5.9 | 10.8 | 11.1 | 7.3 |
| Cash from operations | 54.2 | 48.0 | 52.6 | 38.2 | 51.6 | 65.8 | 60.9 | 94.7 |
| |
| Capital expenditures [+] | -54.0 | -28.1 | -20.7 | -35.5 | -35.1 | -28.6 | -19.8 | -31.2 |
| Purchases of property and equipment | -54.0 | -28.1 | -20.7 | -35.5 | | | | |
| Capitalized product costs | | | | | -35.1 | -28.6 | -19.8 | -31.2 |
| Sales of property and equipment | 0.7 | 0.5 | 0.1 | 0.1 | 0.1 | 0.5 | | |
| Sales of short-term investments, net [+] | | | 2.3 | 2.0 | 1.0 | 5.8 | -7.3 | |
| Purchases of short-term investments | | | | | | | -7.3 | |
| Sales of short-term investments | | | 2.3 | 2.0 | 1.0 | 5.8 | | |
| Other cash from investing | | | 0.1 | 3.2 | 8.0 | | -22.2 | 0.6 |
| Cash from investing | -53.4 | -27.5 | -18.2 | -30.2 | -26.0 | -22.3 | -49.3 | -30.5 |
| |
| Cash dividends paid | | | -1.2 | -5.0 | -4.9 | -4.9 | -4.8 | -4.8 |
| Financing costs | -2.1 | -0.4 | -1.9 | -1.2 | -0.7 | | -2.1 | |
| Other cash from financing | -2.3 | -27.1 | -36.3 | -11.1 | -17.6 | -34.9 | -15.0 | -56.9 |
| Cash from financing | -0.2 | -26.7 | -35.6 | -14.8 | -21.8 | -39.8 | -17.7 | -61.7 |
| |
| Free cash flow | 0.1 | 19.9 | 31.9 | 2.7 | 51.6 | 65.8 | 60.9 | 94.7 |
| Per share (diluted) | $0.00 | $0.65 | $1.05 | $0.09 | $0.55 | $1.25 | $1.40 | $2.19 |
| |
| Cash paid for interest | 8.1 | 8.7 | 11.0 | 11.6 | 11.4 | 11.7 | 12.4 | 14.1 |