| In millions, except per share items | Dec-31-22 | Dec-05-22 | Dec-31-21 | Dec-05-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 |
| | 10-K | 8-K | 10-K | 8-K | 10-K | 10-K | S-1/A |
| Net income | -40.3 | -40.3 | -23.9 | -23.9 | -14.5 | -1.1 | -9.2 |
| Depreciation and amortization [+] | 1.1 | 1.1 | 1.0 | 1.0 | 0.5 | 0.3 | 0.1 |
| Depreciation | 1.1 | 1.1 | 1.0 | 1.0 | 0.5 | 0.3 | 0.1 |
| Amortization of intangible assets | | | | | 0.0 | | |
| Asset impairment charges | 15.6 | 12.8 | 0.4 | 0.4 | 0.2 | | |
| Stock-based compensation | 0.6 | 0.6 | 4.0 | 4.0 | 2.4 | 0.9 | 0.9 |
| Change in working capital [+] | -3.6 | 5.1 | -9.2 | -4.2 | -2.0 | -4.3 | -2.4 |
| Accounts receivable | | -0.3 | | -0.4 | | | -0.3 |
| Inventories | 1.7 | 1.7 | -3.6 | -3.6 | -3.9 | -1.3 | -0.5 |
| Other current assets | 1.6 | 1.6 | -1.0 | -1.0 | -2.3 | -0.1 | |
| Accounts payable | 0.2 | 0.2 | -0.5 | -0.5 | 0.6 | -0.1 | 0.6 |
| Accrued expenses | 1.9 | 1.9 | 1.3 | 1.3 | 0.4 | 0.2 | |
| Other | -9.0 | | -5.4 | | 3.1 | -3.0 | -2.3 |
| Other operating activities | 12.3 | 6.4 | 5.5 | 0.5 | -1.3 | -5.2 | 1.1 |
| Cash from operations | -14.3 | -14.3 | -22.1 | -22.1 | -14.7 | -9.4 | -9.5 |
| |
| Capital expenditures [+] | -1.2 | -1.2 | -1.7 | -1.6 | -1.1 | -2.4 | -0.6 |
| Purchases of property and equipment | -1.2 | -1.2 | -1.6 | -1.6 | -1.1 | -2.4 | -0.6 |
| Capitalized product costs | 0.0 | | -0.2 | | | | |
| Sales of property and equipment | 0.0 | | 0.0 | | | | |
| Acquisitions | | | -10.4 | -10.4 | | | |
| Purchases of short-term investments, net | 8.5 | | | | -3.2 | -5.5 | |
| Purchases of short-term investments | | | | | -8.2 | -12.5 | |
| Sales of short-term investments | 8.5 | | | | 5.0 | 7.0 | |
| Other cash from investing | 1.6 | 10.1 | -0.5 | -0.6 | | 0.0 | -0.2 |
| Cash from investing | 9.0 | 9.0 | -12.6 | -12.6 | -4.3 | -7.9 | -0.7 |
| |
| Issuance of common stock, net | 0.0 | | -0.2 | | 66.1 | 8.6 | 4.1 |
| Option exercises | 0.1 | | 0.8 | | 0.2 | 0.1 | |
| Other cash from financing | 0.2 | 0.1 | 1.5 | 0.6 | 9.3 | -7.5 | 20.1 |
| Cash from financing | 0.1 | 0.1 | 0.6 | 0.6 | 75.2 | 1.0 | 24.2 |
| |
| Free cash flow | -15.5 | -15.5 | -23.7 | -23.7 | -15.7 | -11.9 | -10.0 |
| Per share (diluted) | ($1.69) | ($1.69) | ($2.65) | ($2.64) | ($2.84) | ($3.23) | ($2.83) |
| |
| Cash paid for interest | 0.0 | | | | | 0.0 | |