| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 8-K | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Revenue | 187.5 | 219.1 | 268.1 | 330.4 | 372.2 | 389.9 | 380.2 | 343.0 |
| Revenue growth | -49.6% | -43.8% | -29.5% | -3.7% | 23.7% | 84.5% | 122.0% | 148.1% |
| Costs and expenses: | | | | | | | | |
| Cost of revenue | 29.5 | 34.9 | 30.7 | 34.8 | 34.9 | 30.3 | 25.2 | 19.8 |
| Research and development | 24.0 | | 52.0 | 60.9 | 65.7 | 57.6 | 46.2 | 40.6 |
| Sales and marketing | 154.5 | 195.1 | 277.6 | 399.2 | 461.9 | 487.7 | 466.7 | 389.9 |
| General and administrative | 101.7 | 98.5 | 163.2 | 174.7 | 202.8 | 201.3 | 135.8 | 119.0 |
| Total costs and expenses | 477.8 | 529.9 | 691.5 | 717.1 | 765.3 | 776.9 | 674.0 | 569.3 |
| Loss from operations | -290.3 | -310.8 | -423.4 | -386.7 | -393.1 | -387.0 | -293.8 | -226.3 |
| Operating margin | -154.9% | -141.9% | -157.9% | -117.1% | -105.6% | -99.2% | -77.3% | -66.0% |
| Gain on extinguishment of debt | 15.2 | | | | | | | |
| Interest expense, net | -13.4 | -19.3 | -24.0 | -20.6 | -16.9 | -9.4 | -1.2 | -0.2 |
| Change in fair value of common stock warrant liabilities | 0.7 | | 6.0 | 11.4 | 125.1 | 94.5 | 87.9 | 81.9 |
| Other income (expense), net | 0.2 | | 0.1 | 0.3 | -0.2 | 0.0 | 0.0 | -0.5 |
| Loss before income taxes | -252.1 | | -441.2 | -395.6 | -285.1 | -301.8 | -207.1 | -145.1 |
| Provision for (benefit from) income taxes | 0.1 | -0.1 | -0.3 | -0.8 | -19.6 | -19.4 | -19.1 | -18.8 |
| Net loss | -287.7 | -328.4 | -440.9 | -394.8 | -265.5 | -282.4 | -187.9 | -126.3 |
| |
| Net loss per share attributable to common stockholders: | | | | | | | | |
| Basic (in dollars per share) | ($1.61) | | ($4.00) | ($3.90) | ($3.58) | ($0.72) | ($0.50) | ($0.38) |
| Diluted (in dollars per share) | ($1.61) | | ($4.00) | ($3.91) | ($3.88) | ($1.02) | ($0.81) | ($0.26) |
| |
| Weighted average shares outstanding: | | | | | | | | |
| Basic (in shares) | 211.2 | | 311.5 | 305.1 | 300.4 | 391.8 | 380.6 | 358.1 |
| Diluted (in shares) | 211.2 | | 311.5 | 306.1 | 301.7 | 393.0 | 382.6 | 359.1 |
| |
| Other comprehensive income (loss): | | | | | | | | |
| Change in unrealized loss on available-for-sale investments, net of tax | -0.9 | | | | | | | |
| Total other comprehensive income (loss): | 1.7 | | -1.3 | -2.7 | -2.9 | -2.3 | -0.2 | |
| Total comprehensive loss | -285.0 | -326.6 | -442.2 | -397.5 | -268.3 | -284.7 | -188.2 | -82.4 |