| In millions, except per share items | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 | Dec-31-20 |
| | 10-Q | 10-Q | 10-Q | 8-K | 10-Q | 10-Q | 10-Q | 10-K |
| Cash flows from operating activities | | | | | | | | |
| Net loss | -35.4 | -14.3 | -18.4 | -124.2 | -19.1 | -20.2 | -8.5 | -6.5 |
| |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | | | |
| Depreciation and amortization | 0.6 | 0.5 | 0.4 | | 0.3 | 0.3 | 0.2 | |
| Amortization expense - right-of-use assets - operating leases | 0.8 | 0.5 | 0.5 | | | | | |
| Stock-based compensation, net of amounts capitalized | 10.9 | 12.4 | 16.6 | | 0.6 | 0.5 | 0.6 | |
| Issuance of warrants for services | | | | | 0.3 | 1.4 | | |
| Change in fair value of warrants | -1.4 | -23.6 | -22.2 | 8.2 | | -0.1 | 0.1 | |
| Net amortization of premiums and accretion of discounts on investments | | | | | 0.0 | 0.1 | 0.1 | |
| Amortization of debt discount | | | | | 2.1 | 1.7 | | |
| Change in the fair value of derivative liability | -1.4 | -45.7 | | | 1.0 | 4.8 | | |
| Loss on sale of property, equipment and software | -0.1 | | | | | | | |
| Issuance of common stock for services | -1.4 | -23.6 | -22.2 | 8.2 | | -0.1 | 0.1 | |
| Changes in operating assets and liabilities: | | | | | | | | |
| Prepaid expenses and other current assets | -3.1 | 5.5 | 0.7 | | 1.5 | -2.5 | 0.0 | -0.2 |
| Other assets | 0.9 | -3.5 | -0.1 | | -0.1 | -3.1 | -0.1 | 0.0 |
| Accounts payable | -1.0 | 0.4 | 1.6 | | 1.1 | 1.4 | 0.3 | |
| Other long-term liabilities | | | 0.1 | | 0.0 | | | |
| Accrued expenses and other current liabilities | 1.8 | 0.0 | 2.6 | | -0.5 | 2.4 | 0.5 | 0.1 |
| Net cash used in operating activities | -26.0 | -22.0 | -18.2 | -66.0 | -12.8 | -13.3 | -6.8 | -6.8 |
| |
| Cash flows from investing activities | | | | | | | | |
| Maturities of investments | | | | | 13.0 | 17.0 | 18.2 | |
| Proceeds from sale of property, equipment and software | 0.4 | | | | | | | |
| Purchase of property, equipment and software | -3.8 | -2.7 | -1.7 | | -0.8 | -0.6 | -1.0 | -2.2 |
| Deposit for purchase of trucks | | | | | | -0.4 | | |
| Refund of deposit for trucks | | | | | | 0.0 | | |
| Net cash provided by (used in) investing activities | -3.4 | -2.7 | -1.7 | 49.5 | 12.2 | 16.1 | 17.3 | 4.4 |
| |
| Cash flows from financing activities | | | | | | | | |
| Cash proceeds received from convertible note payable | | | | | 0.0 | 25.0 | | |
| Payment towards notes payable | -0.1 | -0.1 | -0.1 | | 0.0 | -0.1 | -0.1 | -0.3 |
| Proceeds from exercise of stock options | 0.2 | 0.8 | 0.4 | | 0.1 | 0.0 | 0.1 | |
| Repurchase of early exercised stock options | | | 0.0 | | | | | |
| Deferred offering costs | | | | | -0.8 | | | |
| Net cash provided by financing activities | 0.0 | 0.6 | 0.3 | 270.1 | -0.8 | 24.9 | 0.0 | 0.0 |
| Net increase (decrease) in cash, cash equivalents and restricted cash | -29.4 | -24.1 | -19.7 | | -1.4 | 27.7 | 10.5 | |
| |
| Supplemental disclosures of cash flow information: | | | | | | | | |
| Cash paid during the period for interest | | | 0.0 | | 0.0 | 0.0 | 0.0 | |
| Supplemental schedule of noncash investing and financing activities | | | | | | | | |
| Acquisition of property, equipment and software in accounts payable | 0.7 | 0.1 | 0.3 | | | -0.1 | 0.2 | |
| Acquisition of trucks by assuming notes payable | 0.4 | 1.0 | | | | | 0.3 | |
| Right-of-use assets obtained in exchange for lease obligations | 17.7 | 0.5 | 6.6 | | | | | |
| Deferred offering costs in accrued liability | | | | | 1.1 | 2.2 | | |
| Stock-based compensation capitalized into internally developed software | 0.2 | 0.8 | 0.2 | | 0.1 | 0.1 | 0.0 | |
| Vesting of early exercised stock options | 0.0 | 0.0 | 0.0 | | 0.0 | 0.0 | 0.0 | |
| Issuance of common stock for services | | 0.7 | | | | | | |