| In millions, except per share items | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 | Mar-31-21 | Dec-31-20 | Sep-30-20 |
| | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q |
| Operating activities | | | | | | | | |
| Net income | 2.5 | 0.0 | 3.8 | -2.3 | 3.7 | 14.4 | -3.5 | -11.8 |
| |
| Adjustments to reconcile net income to net cash from operating activities: | | | | | | | | |
| Non-cash interest expense | 1.3 | 1.5 | 1.6 | 1.9 | 2.0 | 1.7 | 1.0 | 1.9 |
| Share-based compensation expense | 1.4 | 1.3 | 1.2 | 1.2 | 1.0 | 1.1 | 0.8 | 1.4 |
| Amortization of intangible assets | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.3 |
| Unrealized loss on short-term investments and securities sold, not yet purchased | 0.4 | | | | | | | |
| Amortization of right-of-use lease assets | 0.0 | 0.0 | 0.0 | 0.1 | 0.1 | 0.0 | 0.2 | 0.4 |
| Depreciation expense | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 |
| Gain on forgiveness of Paycheck Protection Program loan | | -2.3 | | | | | | |
| Gain on sale of non-controlling equity interest | | -0.7 | | | | | | |
| (Gain) loss on change in fair value of contingent value rights | 0.0 | -0.2 | | | -0.1 | 0.5 | | |
| Loss on foreign currency exchange | 0.4 | | | | | | | |
| Inventory fair value step-up adjustment included in cost of product sales | | | | | | 0.9 | 1.3 | 1.2 |
| Changes in operating assets and liabilities: | | | | | | | | |
| Accounts receivable, net | -0.2 | 2.9 | 0.2 | -0.2 | -4.4 | 1.7 | -1.9 | -0.9 |
| Inventory, net | -1.2 | -0.8 | -0.2 | -0.6 | -0.1 | -0.2 | 0.0 | -0.6 |
| Prepaid expenses and other current assets | 1.7 | 0.2 | -1.5 | 0.9 | 0.9 | -2.7 | -0.1 | 0.8 |
| Accounts payable | 0.4 | -0.1 | -3.8 | -0.6 | 0.9 | -0.6 | -4.6 | -1.9 |
| Accrued expenses and other current liabilities | 1.1 | -0.6 | -4.8 | -0.9 | 0.1 | 1.1 | -5.6 | -2.4 |
| Deferred revenue | | | | | 2.8 | | | |
| Lease liabilities | 0.0 | 0.0 | -0.1 | -0.1 | -0.1 | 0.0 | -0.2 | -0.6 |
| Net cash provided by operating activities | 6.7 | 2.5 | 3.2 | 0.8 | 7.1 | 17.2 | -7.3 | -9.8 |
| |
| Investing activities | | | | | | | | |
| Proceeds from securities sold, not yet purchased | 0.3 | | | | | | | |
| Net cash provided by investing activities | 0.3 | | | 0.0 | | | | -30.8 |
| |
| Financing activities | | | | | | | | |
| Purchases of common stock under stock repurchase plan | -2.9 | -5.2 | -3.4 | | | | | |
| Net proceeds from issuance of common stock under ESPP | 0.1 | 0.2 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Net proceeds from issuance of common stock under 2013 Equity Plan | | | | 0.0 | 0.0 | 0.2 | | |
| Net cash (used for) provided by financing activities | -2.8 | -5.0 | -3.3 | 0.1 | 0.1 | 0.2 | 0.1 | 0.1 |
| Net increase in cash, cash equivalents and restricted cash | 1.7 | | | | 24.7 | | | |
| |
| Supplemental disclosure of non-cash investing and financing activities | | | | | | | | |
| Forgiveness of Paycheck Protection Program loan | | 2.3 | | | | | | |
| Sale of non-controlling equity interest | | 0.7 | | | | | | |
| |
| Reconciliation of cash, cash equivalents and restricted cash to the condensed consolidated balance sheets | | | | | | | | |
| Cash and cash equivalents | | | | | | | | |
| Restricted cash | | | | | | | | |