Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating activities
Net income	$ 2,458	$ 3,733	$ 2,460	$ 18,151
Adjustments to reconcile net income to net cash provided by operating activities:
Non-cash interest expense			2,771	3,718
Share-based compensation expense			2,614	2,140
Amortization of intangible assets	400	400	776	776
Unrealized loss on short-term investments and securities sold, not yet purchased			406
Amortization of right-of-use lease assets			86	117
Depreciation expense			48	56
Gain on forgiveness of Paycheck Protection Program loan			(2,325)
Gain on sale of non-controlling equity interest			(699)
(Gain) loss on change in fair value of contingent value rights			(140)	370
Loss on foreign currency exchange			385
Inventory fair value step-up adjustment included in cost of product sales				850
Changes in operating assets and liabilities:
Accounts receivable, net			2,683	(2,762)
Inventory, net			(2,018)	(318)
Prepaid expenses and other current assets			1,896	(1,813)
Accounts payable			(153)	(920)
Accrued expenses and other current liabilities			499	1,217
Deferred revenue				2,849
Lease liabilities			(86)	(117)
Net cash provided by operating activities			9,203	24,314
Investing activities
Proceeds from securities sold, not yet purchased			271
Net cash provided by investing activities			271
Financing activities
Purchases of common stock under stock repurchase plan			(8,064)
Net proceeds from issuance of common stock under ESPP			260	198
Net proceeds from issuance of common stock under 2013 Equity Plan				155
Net cash (used for) provided by financing activities			(7,804)	353
Net increase in cash, cash equivalents and restricted cash			1,670	24,667
Cash, cash equivalents and restricted cash, beginning of period			46,708	21,261
Cash, cash equivalents and restricted cash, end of period	48,378	45,928	48,378	45,928
Supplemental disclosure of non-cash investing and financing activities
Forgiveness of Paycheck Protection Program loan			2,325
Sale of non-controlling equity interest			699
Reconciliation of cash, cash equivalents and restricted cash to the condensed consolidated balance sheets
Cash and cash equivalents	48,338	45,888	48,338	45,888
Restricted cash	40	40	40	40
Cash, cash equivalents and restricted cash, end of period	$ 48,378	$ 45,928	$ 48,378	$ 45,928