| 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/A | 10-K/A | 10-K/A | 10-K | 10-K/A |
| Net income | -24.2 | -32.7 | -32.9 | -32.2 | -10.6 | -1.1 | -1.1 | -0.7 |
| Depreciation and amortization [+] | 2.5 | 0.7 | 3.1 | 2.9 | 0.3 | 0.2 | 0.2 | 0.2 |
| Depreciation | 2.1 | 0.4 | 2.6 | 2.4 | 0.2 | 0.2 | 0.2 | 0.1 |
| Amortization of intangible assets | 0.4 | 0.3 | 0.5 | 0.5 | 0.1 | | | 0.1 |
| Asset impairment charges | | | 0.7 | 0.7 | | 0.1 | 0.1 | 0.2 |
| Stock-based compensation | 7.8 | 1.1 | 1.6 | 4.7 | 1.8 | 0.5 | 0.2 | 0.2 |
| Deferred taxes | | | | | -0.2 | | | |
| Change in working capital [+] | -7.9 | -2.5 | 4.6 | 6.7 | 1.1 | -0.1 | 0.0 | 0.5 |
| Accounts receivable | -1.4 | -0.6 | -0.5 | 2.8 | 0.3 | -0.3 | 0.3 | 0.6 |
| Inventories | -2.0 | 0.2 | 0.8 | 0.0 | 0.1 | 0.2 | 0.1 | 0.0 |
| Other current assets | -5.5 | -1.6 | -1.0 | 1.2 | -0.8 | -0.1 | 0.0 | 0.0 |
| Accounts payable | | | | | | | -0.3 | -0.2 |
| Other | 1.1 | -0.4 | 5.4 | 2.7 | 1.5 | 0.2 | -0.1 | 0.1 |
| Other operating activities | -39.8 | 22.2 | 12.7 | 6.8 | 3.5 | 0.1 | | 0.1 |
| Cash from operations | -61.7 | -11.2 | -10.3 | -10.4 | -4.1 | -0.4 | -0.5 | 0.7 |
| |
| Capital expenditures [+] | -152.0 | -0.6 | -0.2 | -8.9 | -0.4 | -0.1 | -0.3 | -0.1 |
| Purchases of property and equipment | -152.0 | -0.6 | -0.2 | -8.9 | -0.4 | -0.1 | -0.3 | -0.1 |
| Sales of property and equipment | | | | | 0.0 | | | |
| Purchases of intangible assets | | | | 0.0 | -0.1 | | | |
| Acquisitions | -0.2 | -3.6 | | | | | | |
| Sales of short-term investments, net [+] | 1.3 | -1.1 | 0.6 | 1.3 | -1.4 | | | |
| Purchases of short-term investments | -2.8 | -1.4 | | -0.9 | -1.5 | | | |
| Sales of short-term investments | 4.1 | 0.4 | 0.6 | 2.2 | 0.1 | | | |
| Other cash from investing | -182.6 | -2.5 | -3.2 | -13.0 | -6.8 | -0.9 | | |
| Cash from investing | -333.5 | -7.8 | -2.9 | -20.6 | -8.7 | -1.0 | -0.3 | -0.1 |
| |
| Cash dividends paid | 0.0 | 0.0 | 0.0 | | 0.0 | | | |
| Issuance of common stock, net | 186.9 | 40.0 | | -0.1 | | | | -0.1 |
| Option exercises | | | | 0.1 | 0.6 | | | |
| Other cash from financing | 211.1 | -2.7 | 12.9 | 30.7 | 13.8 | 1.3 | | |
| Cash from financing | 397.9 | 37.3 | 12.9 | 30.5 | 13.2 | 1.3 | 0.0 | -0.1 |
| |
| Free cash flow | -213.7 | -11.8 | -10.5 | -19.3 | -4.5 | -0.4 | -0.8 | 0.6 |
| Per share (diluted) | ($3.85) | ($1.22) | ($7.29) | ($266.79) | ($7.25) | ($0.06) | ($0.12) | $0.08 |
| |
| Cash paid for interest | 0.3 | 0.7 | 1.9 | 0.8 | 0.3 | | | |