| In millions, except per share items | Dec-31-22 | Dec-05-22 | Dec-31-21 | Dec-05-21 | Dec-31-20 | Dec-05-20 | Dec-31-19 |
| | 10-K | 8-K | 10-K | 8-K | 10-K | 8-K | 10-K |
| Net income | -42.8 | 0.0 | -20.7 | 0.0 | -4.3 | 0.0 | -4.9 |
| Depreciation and amortization | 2.1 | 2.1 | 0.7 | 0.7 | 1.2 | | 0.8 |
| Asset impairment charges | 0.3 | 0.3 | | | | | |
| Stock-based compensation | 8.1 | 8.1 | 3.4 | 3.4 | 0.9 | | 0.8 |
| Change in working capital [+] | -8.7 | -8.0 | -1.0 | 1.4 | -4.2 | | -5.3 |
| Accounts receivable | -11.0 | -11.0 | -4.2 | -4.2 | -4.3 | | -6.0 |
| Inventories | -8.8 | -8.8 | -2.7 | -2.7 | -2.3 | | -2.8 |
| Other current assets | -0.7 | 0.0 | -2.4 | | -0.1 | | -0.1 |
| Accounts payable | 4.6 | 4.6 | 1.8 | 1.8 | 1.3 | | -0.2 |
| Accrued expenses | 7.1 | 7.1 | 6.6 | 6.6 | 1.1 | | 3.9 |
| Other operating activities | 10.3 | -33.1 | 0.4 | -22.7 | 1.9 | | 0.9 |
| Cash from operations | -30.6 | -30.6 | -17.2 | -17.2 | -4.5 | | -7.7 |
| |
| Capital expenditures | -14.8 | -14.8 | -2.7 | -2.7 | -1.1 | | -1.2 |
| Purchases of property and equipment | -14.8 | -14.8 | -2.7 | -2.7 | -1.1 | | -1.2 |
| Purchases of short-term investments, net | -61.7 | 1.7 | | | | | |
| Purchases of short-term investments | -63.4 | | | | | | |
| Sales of short-term investments | 1.7 | 1.7 | | | | | |
| Other cash from investing | | -63.4 | | | | | |
| Cash from investing | -76.5 | -76.5 | -2.7 | -2.7 | -1.1 | | -1.2 |
| |
| Issuance of common stock, net | | | 107.6 | | | | |
| Option exercises | 2.2 | 2.2 | 1.8 | 1.8 | 0.4 | | 0.1 |
| Financing costs | -1.0 | -1.0 | | | -0.2 | | -0.3 |
| Other cash from financing | 22.0 | 22.0 | 1.9 | 109.5 | 11.7 | | 19.5 |
| Cash from financing | 20.8 | 20.8 | 107.7 | 107.7 | 11.5 | | 19.7 |
| |
| Free cash flow | -45.5 | -45.5 | -19.9 | -19.9 | -5.6 | | -8.9 |
| Per share (diluted) | ($0.82) | ($822.88) | ($0.41) | ($410.98) | ($0.15) | | ($0.24) |
| |
| Cash paid for interest | 4.4 | 4.4 | 3.9 | 3.9 | 1.1 | | 0.7 |