| In millions, except per share items | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -9.4 | -9.5 | -6.6 | -0.7 | -13.8 | -13.7 | -13.7 | -12.6 |
| Depreciation and amortization [+] | 0.1 | 0.4 | 0.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 |
| Depreciation | 0.0 | 0.0 | 0.0 | | 0.0 | 0.0 | 0.0 | 0.0 |
| Amortization of intangible assets | 0.1 | 0.3 | 0.1 | 0.0 | | | | 0.1 |
| Stock-based compensation | 0.8 | 2.1 | 0.3 | 0.1 | 0.8 | 0.8 | 0.8 | 0.4 |
| Change in working capital [+] | 0.3 | 0.5 | 1.1 | 0.1 | 2.0 | -2.4 | 0.9 | 0.0 |
| Other current assets | 0.1 | 0.1 | -0.1 | 0.0 | 2.0 | -1.9 | 0.2 | -0.2 |
| Other | 0.2 | 0.5 | 1.2 | 0.0 | 0.0 | -0.5 | 0.7 | 0.2 |
| Other operating activities | 3.8 | 3.6 | 2.9 | 0.3 | | | | |
| Cash from operations | -4.4 | -2.8 | -2.3 | -0.2 | -10.9 | -15.2 | -11.9 | -12.2 |
| |
| Capital expenditures | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Purchases of property and equipment | | | | | | | 0.0 | 0.0 |
| Purchases of short-term investments, net | | | | | | -8.5 | | |
| Purchases of short-term investments | | | | | | -21.0 | | |
| Sales of short-term investments | | | | | | 12.5 | | |
| Other cash from investing | | | 0.2 | | 8.5 | | | |
| Cash from investing | 0.0 | 0.0 | 0.2 | 0.0 | 8.5 | -8.5 | 0.0 | 0.0 |
| |
| Issuance of common stock, net | 2.0 | 2.9 | 0.1 | 0.2 | | | 9.2 | 25.7 |
| Other cash from financing | 2.6 | 0.3 | 2.1 | | | | | 9.5 |
| Cash from financing | 4.5 | 3.2 | 2.2 | 0.2 | 0.0 | 0.0 | 9.2 | 35.2 |
| |
| Free cash flow | -4.4 | -2.8 | -2.3 | -0.2 | -10.9 | -15.2 | -11.9 | -12.2 |
| Per share (diluted) | ($0.01) | ($0.03) | ($0.04) | ($0.04) | ($0.41) | ($0.57) | ($0.47) | ($0.72) |
| |
| Cash paid for interest | 0.3 | 0.1 | | | | | | |
| Cash paid for income taxes | 0.0 | 0.0 | | | | | | |