| In millions, except per share items | Jun-30-23 | Dec-31-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 |
| | 10-Q | 8-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Net income | -11.5 | -26.0 | -35.5 | -37.6 | -33.3 | -50.3 | -47.0 | -50.4 |
| Depreciation and amortization [+] | | | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 | 0.7 |
| Depreciation | | | 0.7 | 0.7 | 2.3 | 0.2 | 0.6 | 0.7 |
| Amortization of intangible assets | | | | | -1.6 | 0.5 | | |
| Stock-based compensation | | | 10.1 | 7.0 | 8.6 | | 7.8 | 7.8 |
| Change in working capital [+] | | | -3.5 | -18.3 | -1.7 | | 1.2 | -10.0 |
| Accounts receivable | | | 2.2 | -5.0 | -5.6 | | -3.2 | -1.2 |
| Inventories | | | -1.0 | -6.9 | -0.3 | | -1.4 | -2.0 |
| Other | | | -4.8 | -6.4 | 4.1 | | 5.8 | -6.8 |
| Other operating activities | | | 0.4 | 1.5 | -0.1 | | -0.5 | -1.7 |
| Cash from operations | -11.5 | | -27.9 | -46.7 | -25.9 | -49.5 | -38.0 | -53.5 |
| |
| Capital expenditures [+] | 0.0 | | 0.0 | -0.1 | 0.0 | 0.0 | -0.2 | -1.2 |
| Capitalized product costs | | | 0.0 | -0.1 | 0.0 | | -0.2 | -1.2 |
| Purchases of intangible assets | | | | | 0.0 | | 0.0 | 0.0 |
| Purchases of short-term investments, net | | | 45.7 | -52.9 | -5.5 | | 1.9 | -54.2 |
| Purchases of short-term investments | | | -69.5 | -163.5 | -96.1 | | -101.8 | -115.2 |
| Sales of short-term investments | | | 115.1 | 110.6 | 90.7 | | 103.7 | 60.9 |
| Other cash from investing | | | | | | | | -11.8 |
| Cash from investing | 0.0 | | 45.6 | -53.0 | -5.5 | 0.0 | 1.7 | -67.2 |
| |
| Issuance of common stock, net | | | | | 196.7 | | | |
| Option exercises | | | 1.3 | 0.4 | 8.7 | | 1.3 | 5.0 |
| Other cash from financing | | | 2.7 | 0.8 | 17.6 | | 2.6 | 10.0 |
| Cash from financing | 0.0 | | 1.3 | 0.4 | 205.7 | 0.0 | 1.3 | 5.0 |
| |
| Free cash flow | -11.5 | | -27.9 | -46.7 | -25.9 | -49.5 | -38.0 | -53.5 |
| Per share (diluted) | ($0.08) | | ($0.20) | ($0.33) | ($0.20) | ($0.39) | ($0.30) | ($0.43) |
| |
| Cash paid for income taxes | | | -0.8 | | 0.0 | | -0.2 | |