| In millions, except per share items | Jun-30-23 | Jun-05-23 | Mar-31-23 | Dec-31-22 | Dec-05-22 | Sep-30-22 | Sep-05-22 | Jun-30-22 |
| | 10-Q | 8-K | 10-Q | 10-K | 8-K | 10-Q | 8-K | 10-Q |
| Cash flows from operating activities | | | | | | | | |
| Net loss | 15.3 | | 6.2 | 22.2 | | -22.3 | | -17.3 |
| |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | | | |
| Depreciation | 0.5 | | 0.5 | | | 0.6 | | 0.5 |
| Accretion of debt discount and amortization of debt issuance costs | 0.5 | | 0.5 | | | 0.5 | | 0.5 |
| Stock-based compensation expense | 10.5 | | 10.3 | | | 9.7 | | 8.4 |
| Provision for credit losses | 0.3 | | 0.2 | | | 0.4 | | 0.2 |
| Provision for excess and obsolete inventories | 0.2 | | 0.1 | | | 0.1 | | 0.1 |
| Loss on disposal of property and equipment | | | 0.1 | | | 0.1 | | 0.1 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Accounts receivable | -1.1 | | 0.2 | 2.4 | | -0.6 | | -0.2 |
| Inventory | -0.4 | | -0.4 | 0.6 | | -1.5 | | -1.3 |
| Prepaid expenses and other current assets | -0.5 | | -0.9 | 2.4 | | 3.1 | | 3.3 |
| Other noncurrent assets | -0.1 | | 0.0 | | | 0.2 | | 3.0 |
| Accounts payable | 0.8 | | 1.1 | 0.0 | | 0.2 | | -2.0 |
| Accrued compensation | -0.6 | | 1.1 | 1.4 | | 3.4 | | 2.2 |
| Accrued and other current liabilities | -1.9 | | -0.2 | | | 1.6 | | -0.8 |
| Other noncurrent liabilities | 0.3 | | 0.3 | | | 0.3 | | 0.3 |
| Net cash used in operating activities | -66.6 | | -71.4 | -55.8 | | -71.2 | | -67.5 |
| |
| Cash flows from investing activities | | | | | | | | |
| Purchases of property and equipment | 1.3 | | 1.1 | 1.2 | | 0.6 | | 0.6 |
| Net cash used in investing activities | -0.6 | | -0.9 | -0.7 | | -1.0 | | -1.0 |
| |
| Cash flows from financing activities | | | | | | | | |
| Proceeds from exercise of common stock options | 0.5 | | 0.5 | 0.6 | | 0.5 | | 0.4 |
| Net cash provided by financing activities | 1.6 | | 1.0 | 1.2 | | 0.5 | | 253.0 |
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| Supplemental disclosure of cash flow information | | | | | | | | |
| Cash paid for interest | 3.8 | | 3.5 | 3.3 | | 3.1 | | 3.1 |
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| Supplemental noncash disclosure | | | | | | | | |
| Acquisition of property and equipment included in accounts payable and accrued liabilities | 0.0 | | -0.3 | 0.3 | | 0.1 | | 0.3 |