| 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 | -14.1 | -18.5 | -3.4 | 0.2 | 14.6 | -12.0 | -19.1 | -15.9 |
| Depreciation and amortization [+] | 3.1 | 1.7 | 2.0 | 1.9 | 1.6 | 1.4 | 1.1 | 0.6 |
| Depreciation | 1.5 | 1.6 | 1.9 | 1.7 | 1.4 | 1.0 | 0.7 | 0.3 |
| Amortization of intangible assets | 1.6 | 0.2 | 0.2 | 0.2 | 0.2 | 0.4 | 0.4 | 0.4 |
| Asset impairment charges | | 0.2 | 0.4 | | | | 0.3 | |
| Stock-based compensation | 8.0 | 5.7 | 2.8 | 1.8 | 2.5 | 2.9 | 3.7 | 3.4 |
| Deferred taxes | | | | | | -0.9 | -0.1 | |
| Change in working capital [+] | -5.7 | -0.2 | -6.3 | -1.7 | 3.3 | 0.8 | -0.7 | 0.3 |
| Accounts receivable | -1.9 | -1.8 | -0.9 | -0.1 | -0.4 | 1.4 | -2.1 | -0.4 |
| Inventories | -2.3 | -0.3 | -0.7 | -2.3 | 0.4 | -0.8 | -0.4 | -0.3 |
| Other current assets | -4.3 | -0.6 | -0.3 | -0.5 | -0.1 | 0.3 | -0.2 | -0.5 |
| Other | 2.8 | 2.5 | -4.5 | 1.2 | 3.4 | -0.1 | 2.0 | 1.5 |
| Other operating activities | 10.4 | 16.1 | 3.4 | -1.3 | -21.4 | -1.0 | 3.7 | 0.4 |
| Cash from operations | 1.7 | 5.1 | -1.1 | 1.0 | 0.7 | -8.8 | -11.2 | -11.1 |
| |
| Capital expenditures [+] | -2.6 | -1.8 | -0.9 | -1.5 | -1.8 | -0.8 | -6.9 | -1.5 |
| Purchases of property and equipment | -2.6 | -1.8 | -0.9 | -1.5 | -1.8 | -0.8 | -6.9 | -1.5 |
| Sales of property and equipment | 6.0 | | 0.0 | 0.0 | | 0.1 | | |
| Purchases of intangible assets | -0.2 | -0.1 | -0.1 | -0.4 | -0.4 | -0.3 | -0.3 | -0.2 |
| Acquisitions | | | | | | | | -3.4 |
| Purchases of short-term investments | | | | | | | -0.1 | |
| Purchases of short-term investments | | | | | | | -0.1 | |
| Other cash from investing | -5.0 | -16.8 | | | 0.0 | 0.0 | -0.1 | |
| Cash from investing | -1.7 | -18.7 | -1.0 | -1.8 | -2.2 | -1.0 | -7.3 | -5.1 |
| |
| Issuance of common stock, net | 22.7 | | | | 0.6 | 4.1 | 20.5 | 0.4 |
| Option exercises | 0.6 | 0.1 | | | | | | |
| Financing costs | | | | | -0.1 | -0.2 | -0.2 | -0.1 |
| Other cash from financing | 32.1 | 51.5 | 1.4 | -1.0 | 3.4 | 0.7 | 4.0 | 10.2 |
| Cash from financing | 54.1 | 51.5 | 1.4 | -1.0 | 4.1 | 4.9 | 24.7 | 10.7 |
| |
| Free cash flow | -0.9 | 3.3 | -2.0 | -0.5 | -1.1 | -9.6 | -18.1 | -12.7 |
| Per share (diluted) | ($0.03) | $0.12 | ($0.08) | ($0.02) | ($0.05) | ($0.48) | ($1.42) | ($1.32) |
| |
| Cash paid for interest | 6.5 | 4.8 | 1.8 | 2.0 | 2.1 | 1.5 | 1.4 | 0.6 |
| Cash paid for income taxes | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |