| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 |
| | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -98.0 | -71.7 | -41.6 | -18.3 | -23.3 |
| Depreciation and amortization [+] | 9.0 | 5.6 | 5.1 | 4.8 | 4.2 |
| Depreciation | 9.0 | 5.6 | 5.1 | 4.8 | 4.2 |
| Asset impairment charges | 0.3 | 0.7 | 0.0 | 1.0 | 1.3 |
| Stock-based compensation | 22.2 | 21.2 | 10.9 | 3.8 | 2.0 |
| Change in working capital [+] | 40.7 | 24.7 | 9.7 | 1.0 | 0.4 |
| Accounts receivable | 7.4 | -13.0 | -3.6 | 2.4 | -7.0 |
| Inventories | -2.0 | -6.6 | -4.2 | -4.0 | 0.2 |
| Other current assets | 3.4 | -3.5 | -1.8 | -4.1 | -1.2 |
| Accounts payable | 2.7 | 3.9 | 0.4 | 0.5 | 1.1 |
| Accrued expenses | 7.8 | 3.0 | 2.7 | | |
| Other | 21.4 | 41.0 | 16.3 | 6.2 | 7.1 |
| Other operating activities | -21.7 | -33.6 | -20.0 | -2.8 | 2.0 |
| Cash from operations | -47.5 | -53.1 | -35.9 | -10.5 | -13.5 |
| |
| Capital expenditures | -8.1 | -15.8 | -3.3 | -8.4 | -7.4 |
| Purchases of property and equipment | -8.1 | -15.8 | -3.3 | -8.4 | -7.4 |
| Purchases of short-term investments, net | -45.9 | | | | |
| Purchases of short-term investments | -64.8 | | | | |
| Sales of short-term investments | 18.9 | | | | |
| Other cash from investing | | | | -0.7 | -1.0 |
| Cash from investing | -54.0 | -15.8 | -3.3 | -9.1 | -8.4 |
| |
| Issuance of common stock, net | | | 190.6 | | |
| Option exercises | 0.8 | 10.3 | 3.6 | 0.6 | 0.2 |
| Financing costs | | -0.3 | | | -0.3 |
| Other cash from financing | 10.5 | 23.6 | 4.5 | 1.6 | 95.4 |
| Cash from financing | 9.7 | 13.6 | 191.5 | 1.0 | 95.6 |
| |
| Free cash flow | -55.6 | -69.0 | -39.1 | -19.0 | -21.0 |
| Per share (diluted) | ($0.81) | ($1.03) | ($1.25) | ($6.57) | ($8.04) |