| In millions, except per share items | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 | Dec-31-14 | Dec-31-13 | Dec-31-12 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Net income | -76.8 | -85.0 | -67.8 | -38.3 | -37.2 | -28.8 | -24.2 | -6.3 |
| Depreciation and amortization [+] | 0.1 | 0.1 | 0.0 | 0.1 | 0.2 | 0.2 | 0.1 | |
| Depreciation | 0.1 | 0.1 | 0.0 | 0.1 | 0.2 | 0.2 | 0.1 | |
| Stock-based compensation | 26.2 | 13.9 | 8.6 | 7.4 | 5.2 | 4.4 | 4.8 | 0.6 |
| Change in working capital [+] | -16.8 | -1.2 | 10.3 | 1.2 | 6.0 | -1.7 | 2.7 | 1.5 |
| Accounts receivable | -15.1 | | | | | | | |
| Inventories | -0.9 | | | | | | | |
| Other current assets | -1.5 | -2.5 | -0.2 | 0.4 | 1.0 | -1.3 | 0.0 | -0.1 |
| Deferred revenues | | | | | 0.0 | 0.0 | 0.6 | |
| Other | 0.8 | 1.3 | 10.4 | 0.8 | 5.0 | -0.3 | 2.0 | 1.6 |
| Other operating activities | -0.4 | 0.0 | -0.7 | -0.5 | 0.3 | 0.2 | 0.5 | 0.0 |
| Cash from operations | -67.7 | -72.2 | -49.6 | -30.1 | -25.6 | -25.7 | -16.1 | -4.1 |
| |
| Capital expenditures | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| Purchases of short-term investments, net | | | | 26.7 | -50.9 | 6.4 | -40.2 | |
| Purchases of short-term investments | | | | -26.5 | -105.6 | -16.2 | -40.2 | |
| Sales of short-term investments | | | | 53.1 | 54.7 | 22.6 | | |
| Other cash from investing | -99.2 | 10.8 | -4.4 | 0.0 | 0.0 | | -0.5 | |
| Cash from investing | -99.2 | 10.8 | -4.4 | 26.7 | -50.9 | 6.4 | -40.7 | 0.0 |
| |
| Issuance of common stock, net | 168.4 | 63.9 | 48.2 | | 64.1 | | 97.7 | |
| Option exercises | 2.1 | 1.6 | 0.1 | 0.3 | 0.7 | 0.1 | 1.3 | |
| Other cash from financing | 4.7 | 3.7 | 0.4 | 0.6 | 1.5 | 0.3 | 2.6 | 0.3 |
| Cash from financing | 171.0 | 66.0 | 48.5 | 0.4 | 64.9 | 0.1 | 99.0 | 0.3 |
| |
| Free cash flow | -67.7 | -72.2 | -49.6 | -30.1 | -25.6 | -25.7 | -16.1 | -4.1 |
| Per share (diluted) | ($1.61) | ($2.54) | ($2.15) | ($1.69) | ($1.48) | ($1.99) | ($1.56) | ($1.20) |