| 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 |
| Revenue | | | | | | | | |
| Total revenue, net | 41.5 | 28.4 | 28.2 | 21.6 | 23.4 | 14.7 | 6.6 | 0.9 |
| Total revenue, net growth | 47.2% | 21.5% | 325.8% | 2266.0% | -53.2% | 50475.9% | -40.4% | 2946.7% |
| Operating expenses | | | | | | | | |
| Cost of sales | 1.6 | 1.4 | 1.6 | 0.3 | 0.5 | 0.3 | 0.3 | 0.0 |
| Selling, general and administrative | 47.1 | | 51.5 | 45.2 | 46.3 | 44.1 | 44.3 | 39.8 |
| Research and development | 12.7 | 9.9 | 11.5 | 12.6 | 11.1 | 20.1 | 10.1 | 9.8 |
| Other (income) expense, net | -3.6 | -2.2 | -0.5 | 1.4 | -0.3 | 0.1 | -1.0 | 1.8 |
| Total cost of sales and operating expenses | 57.7 | 56.5 | 64.2 | 59.5 | 56.1 | 65.0 | 53.8 | 51.5 |
| Loss from operations | -16.2 | -28.1 | -36.0 | -37.9 | -32.7 | -50.4 | -47.1 | -50.5 |
| Operating margin | -39.0% | -98.8% | -127.7% | -175.2% | -139.7% | -343.3% | -712.0% | -5529.9% |
| Interest expense | -0.1 | | | | | | | |
| Interest income | 4.1 | 2.9 | 0.5 | 0.3 | 0.1 | 0.1 | 0.1 | 0.2 |
| Net loss before income taxes | -12.1 | | -35.5 | -37.6 | -32.6 | -50.2 | -47.0 | -50.4 |
| Income tax (benefit) expense | -0.6 | 0.9 | 0.0 | 0.0 | 0.7 | 0.0 | 0.0 | 0.0 |
| Net loss | -11.5 | -26.0 | -35.5 | -37.6 | -33.3 | -50.3 | -47.0 | -50.4 |
| |
| Other comprehensive loss: | | | | | | | | |
| Unrealized (loss) gain on available-for-sale securities, net of tax of nil | 0.0 | | -0.2 | -0.8 | -0.1 | 0.0 | 0.0 | 0.0 |
| Comprehensive loss | -11.5 | | -35.8 | -38.4 | -33.4 | -50.3 | -47.0 | -50.4 |
| |
| Basic loss per share (in usd per share) | ($0.08) | ($0.18) | ($0.25) | ($0.27) | ($0.25) | ($0.39) | ($0.37) | ($0.40) |
| Diluted loss per share (in usd per share) | ($0.08) | ($0.18) | ($0.25) | ($0.27) | ($0.25) | ($0.39) | ($0.37) | ($0.40) |
| |
| Weighted-average common shares outstanding used in computation of basic loss per share | 142.8 | 141.9 | 141.7 | 141.7 | 129.4 | 128.4 | 128.2 | 127.4 |
| Weighted-average common shares outstanding used in computation of diluted loss per share | 142.8 | 141.9 | 141.7 | 141.7 | 129.4 | 128.4 | 128.2 | 127.4 |