| In millions, except per share items | Jun-30-21 | Mar-31-21 | Jun-30-20 | Mar-31-20 | Dec-31-19 | Sep-30-19 | Jun-30-19 | Mar-31-19 |
| | 10-Q | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q |
| Net income | | | -29.7 | -68.1 | -61.4 | -61.1 | -58.8 | -55.8 |
| Depreciation and amortization [+] | | | 3.7 | 3.1 | 2.5 | 2.0 | 1.6 | 1.2 |
| Depreciation | | | 3.7 | 3.1 | 2.5 | 2.0 | 1.6 | 1.2 |
| Asset impairment charges | | | | 3.5 | | | | |
| Stock-based compensation | | | 7.6 | 7.6 | 7.4 | 7.3 | 7.1 | 6.6 |
| Change in working capital [+] | | | -2.4 | -0.8 | -4.7 | -3.5 | -6.6 | -4.3 |
| Accounts receivable | | | 0.7 | 0.0 | 0.0 | -0.6 | -0.9 | -0.3 |
| Inventories | | | 0.5 | 0.2 | -0.6 | -1.7 | -4.4 | -4.5 |
| Other current assets | | | -3.1 | -2.0 | -0.8 | -0.1 | -0.3 | -0.6 |
| Accounts payable | | | 0.3 | 5.0 | 1.8 | 2.0 | 3.7 | -0.1 |
| Accrued expenses | | | -0.7 | -4.0 | -5.0 | -3.2 | -4.7 | 1.2 |
| Other operating activities | | | 0.0 | -0.1 | -0.2 | -0.2 | -0.2 | -0.2 |
| Cash from operations | | | -17.4 | -54.8 | -56.3 | -55.5 | -57.0 | -52.5 |
| |
| Capital expenditures [+] | | | -4.7 | -7.2 | -8.4 | -12.7 | -18.2 | -16.2 |
| Purchases of property and equipment | | | -4.7 | -7.2 | -8.4 | -12.7 | -18.2 | -16.2 |
| Sales of property and equipment | | | 0.0 | | 0.0 | | | 0.3 |
| Purchases of short-term investments, net | | | -2.6 | -12.7 | -39.4 | -26.3 | -22.7 | -0.8 |
| Purchases of short-term investments | | | -127.4 | -121.5 | -125.0 | -95.7 | -60.2 | -40.1 |
| Sales of short-term investments | | | 124.8 | 108.8 | 85.6 | 69.4 | 37.5 | 39.3 |
| Cash from investing | | | -7.3 | -19.9 | -47.8 | -39.0 | -40.9 | -16.7 |
| |
| Issuance of common stock, net | | | | | | | | 92.3 |
| Option exercises | | | 1.1 | 1.5 | 2.0 | 1.9 | 1.8 | 1.5 |
| Other cash from financing | | | 20.7 | 21.5 | 22.7 | 22.5 | 3.1 | 2.5 |
| Cash from financing | | | 19.6 | 20.0 | 63.8 | 63.7 | 44.4 | 93.3 |
| |
| Free cash flow | | | -22.1 | -62.0 | -64.8 | -68.2 | -75.2 | -68.6 |
| Per share (diluted) | | | ($0.56) | ($1.59) | ($1.68) | ($1.86) | ($2.13) | ($2.10) |