| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 |
| | 10-K | 10-K | 10-K | 10-K | 10-K/A | S-1/A |
| Net income | -10.8 | 62.9 | -45.1 | -16.7 | -30.6 | -18.1 |
| Depreciation and amortization | 2.1 | 3.3 | 3.6 | 3.5 | 6.7 | 4.2 |
| Asset impairment charges | 0.2 | | 11.7 | 0.6 | 1.0 | |
| Stock-based compensation | 0.8 | 1.3 | 5.1 | | -0.8 | 0.5 |
| Change in working capital [+] | -2.7 | 1.2 | 15.8 | 11.3 | -1.4 | 2.5 |
| Accounts receivable | 0.3 | -0.1 | 0.4 | -0.2 | -0.9 | 0.2 |
| Other current assets | 0.5 | -0.1 | 0.2 | 0.1 | -0.3 | 0.1 |
| Accounts payable | 0.0 | -0.6 | 0.7 | -1.3 | -0.9 | 1.2 |
| Accrued expenses | -3.2 | 1.1 | 0.7 | 0.6 | 0.6 | 0.2 |
| Other | -0.4 | 0.9 | 13.9 | 12.0 | 0.2 | 0.8 |
| Other operating activities | -0.5 | -68.7 | 3.6 | -6.2 | 10.4 | 0.1 |
| Cash from operations | -10.9 | 0.1 | -5.2 | -7.6 | -14.6 | -10.8 |
| |
| Capital expenditures | 0.0 | -0.2 | -0.4 | -1.3 | -17.1 | -5.9 |
| Purchases of property and equipment | 0.0 | -0.2 | -0.4 | -1.3 | -17.1 | -5.9 |
| Purchases of intangible assets | | | 0.0 | 0.0 | 0.0 | -0.3 |
| Sales of short-term investments, net [+] | -70.0 | 106.0 | | | | |
| Purchases of short-term investments | -70.0 | | | | | |
| Sales of short-term investments | | 106.0 | | | | |
| Other cash from investing | -0.1 | | -5.2 | 10.3 | -5.9 | |
| Cash from investing | -70.1 | 105.9 | -5.5 | 9.0 | -23.1 | -6.1 |
| |
| Issuance of common stock, net | -0.6 | | 7.0 | | | |
| Other cash from financing | | -3.4 | 2.2 | 3.7 | 34.3 | 28.0 |
| Cash from financing | -0.6 | -3.4 | 9.2 | 3.7 | 34.3 | 28.0 |
| |
| Free cash flow | -11.0 | -0.1 | -5.5 | -8.9 | -31.8 | -16.6 |
| Per share (diluted) | ($0.28) | $0.00 | ($0.19) | ($0.55) | ($2.74) | ($5.54) |
| |
| Cash paid for interest | | 0.4 | 2.1 | | 0.1 | |