| Total revenue | $58.7M-2.1% | $59.9M+19.7% | $50.1M |
| Operations and technology | $141.0M+3.3% | $136.5M+35.1% | $101.1M |
| Selling, general, and administrative | $166.5M+15.9% | $143.6M+18.5% | $121.2M |
| Depreciation and amortization | $19.0M+73.8% | $10.9M+32.2% | $8.3M |
| Total operating expenses | $570.9M+8.2% | $527.7M+21.3% | $435.2M |
| Loss from operations | -$89.7M+15.6% | -$106.2M-38.3% | -$76.8M |
| Interest income | $16.5M+224.8% | $5.1M+3839.5% | $129K |
| Interest expense | -$1.6M-59.9% | -$979K-25.2% | -$782K |
| Total other income (expense) | $14.9M+264.2% | $4.1M+728.3% | -$653K |
| Total pre tax book income (loss) | -$74.7M+26.8% | -$102.1M-31.8% | -$77.5M |
| Provision for income taxes | $526K+504.6% | $87K-88.0% | $724K |
| Net loss | -$75.3M+26.4% | -$102.2M-30.7% | -$78.2M |
| Net income (loss) per share attributable to common stockholders: basic | -$470+27.7% | -$650-4.8% | -$620 |
| Net loss per share - diluted | -$470+27.7% | -$650-4.8% | -$620 |
| Weighted-average shares - basic | $159.95B+1.9% | $156.99B+25.3% | $125.33B |
| Weighted-average number of shares of common stock - diluted | $159.95B+1.9% | $156.99B+25.3% | $125.33B |
| Marketplace And Service Revenue [Member] |
| Total revenue | $58.7M-2.1% | $59.9M+19.7% | $50.1M |
| Customer Assurance Revenue [Member] |
| Total revenue | $58.7M-2.1% | $59.9M+19.7% | $50.1M |
| Marketplace And Service Cost [Member] |
| Cost of revenue | $51.7M-1.8% | $52.7M+16.2% | $45.3M |
| Customer Assurance Cost [Member] |
| Cost of revenue | $51.7M-1.8% | $52.7M+16.2% | $45.3M |
