| 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 | -75.4 | -158.6 | -171.3 | -144.6 | -128.6 | -122.7 | -72.1 | -52.6 |
| Depreciation and amortization [+] | 0.2 | 0.3 | 0.3 | 1.6 | 28.4 | 28.0 | 26.5 | 31.9 |
| Depreciation | | | | | | | 0.5 | |
| Amortization | | | | | | | 25.9 | |
| Asset impairment charges | | 3.1 | | | | | | 7.2 |
| Stock-based compensation | 8.5 | 19.8 | 17.8 | 21.8 | 17.5 | 15.1 | 13.7 | 13.9 |
| Change in working capital [+] | -26.4 | 51.6 | 22.3 | 13.9 | 59.6 | 9.4 | -5.5 | 35.3 |
| Accounts receivable | -13.0 | 0.1 | | 29.4 | 2.8 | 7.7 | -9.5 | 40.2 |
| Inventories | -9.2 | | | -2.0 | 3.4 | 4.3 | -5.8 | 1.9 |
| Other current assets | -0.8 | 1.9 | 1.2 | -2.5 | -3.6 | -6.1 | -0.4 | -0.4 |
| Deferred revenues | | | | | | 0.6 | -3.0 | -3.5 |
| Other | -3.4 | 49.6 | 21.1 | -11.0 | 57.0 | 2.9 | 13.2 | -2.9 |
| Other operating activities | -3.9 | -35.6 | 9.3 | -27.4 | -39.3 | 31.3 | -3.1 | -28.9 |
| Cash from operations | -97.0 | -119.5 | -121.6 | -134.6 | -62.4 | -38.9 | -40.5 | 6.7 |
| |
| Capital expenditures [+] | -0.3 | -0.2 | -5.5 | -9.0 | -0.1 | -0.5 | -0.1 | -0.2 |
| Purchases of property and equipment | -0.3 | -0.2 | -5.5 | -9.0 | -0.1 | -0.5 | -0.1 | -0.2 |
| Sales of property and equipment | | | | 0.1 | | | | |
| Purchases of intangible assets | | | | | -2.7 | | | |
| Purchases of short-term investments, net | -34.6 | -16.9 | -89.4 | -200.2 | | | | 3.1 |
| Purchases of short-term investments | -34.6 | -16.9 | -89.4 | -200.2 | | | | |
| Sales of short-term investments | | | | | | | | 3.1 |
| Other cash from investing | 8.1 | 125.8 | 113.0 | 241.1 | 4.1 | -0.6 | -0.6 | |
| Cash from investing | -26.7 | 108.7 | 18.1 | 32.0 | 1.4 | -1.1 | -0.7 | 2.8 |
| |
| Issuance of common stock, net | 20.0 | | | | | 128.3 | 73.9 | |
| Option exercises | 0.3 | 0.7 | 0.7 | 7.1 | 13.5 | 5.5 | 0.9 | 1.5 |
| Other cash from financing | 55.9 | 54.0 | 85.9 | 16.8 | 5.0 | -14.1 | -13.4 | 3.0 |
| Cash from financing | 75.6 | 53.3 | 85.2 | 9.6 | -8.5 | 108.7 | 59.6 | 1.5 |
| |
| Free cash flow | -97.3 | -119.7 | -127.2 | -143.6 | -62.5 | -39.3 | -40.5 | 6.5 |
| Per share (diluted) | ($0.53) | ($0.77) | ($1.02) | ($1.30) | ($0.61) | ($0.46) | ($0.56) | $0.10 |
| |
| Cash paid for interest | 0.8 | | | | 1.0 | 2.7 | 3.3 | 3.3 |
| Cash paid for income taxes | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |