CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Cash flows from operating activities:
Net (loss) income	$ (19,581,000)	$ (13,445,000)	$ 30,874,000	$ (865,000)	$ (33,026,000)	$ 30,009,000
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization					417,000	975,000
Remeasurement of acquisition-related contingent consideration					0	3,396,000
Remeasurement of financing-related contingent consideration					0	435,000
Amortization of debt discount and debt issuance costs	313,000		1,620,000		625,000	3,193,000
Change in deferred tax and income tax deferred charge					(6,228,000)	161,000
Stock-based compensation expense					3,729,000	1,511,000
Gain from the disposition of the hospital products	0	0	(45,760,000)		0	(45,760,000)
Gain from the release of certain liabilities	(88,000)		0		(166,000)	0
Other adjustments					757,000	477,000
Net changes in assets and liabilities
Accounts receivable					0	2,589,000
Inventories					0	(1,353,000)
Prepaid expenses and other current assets					(3,106,000)	(1,149,000)
Research and development tax credit receivable					3,078,000	2,036,000
Accounts payable & other current liabilities					176,000	(1,550,000)
Accrued expenses					1,199,000	(6,906,000)
Accrued income taxes					0	321,000
Earn-out payments for contingent consideration in excess of acquisition-date fair value					0	(3,736,000)
Royalty payments for contingent consideration payable in excess of original fair value					0	(608,000)
Other assets and liabilities					(1,021,000)	(3,458,000)
Net cash used in operating activities					(33,566,000)	(19,417,000)
Cash flows from investing activities:
Purchases of property and equipment					(26,000)	0
Proceeds from the disposition of the hospital products					16,500,000	14,500,000
Proceeds from sales of marketable securities					66,213,000	15,716,000
Purchases of marketable securities					(53,372,000)	(97,878,000)
Net cash provided by (used in) investing activities					29,315,000	(67,662,000)
Cash flows from financing activities:
Proceeds from the February 2020 private placement					0	60,639,000
Proceeds from the May 2020 public offering					0	116,974,000
Proceeds from stock option exercises and employee stock purchase plan					149,000	1,903,000
Net cash provided by financing activities					149,000	179,516,000
Effect of foreign currency exchange rate changes on cash and cash equivalents					(478,000)	(37,000)
Net change in cash and cash equivalents					(4,580,000)	92,400,000
Cash and cash equivalents at January 1,		$ 71,722,000		$ 9,774,000	71,722,000	9,774,000	$ 9,774,000
Cash and cash equivalents at June 30,	$ 67,142,000		$ 102,174,000		67,142,000	102,174,000	$ 71,722,000
Supplemental disclosures of cash flow information:
Interest paid					3,234,000	3,234,000
Income taxes paid (refund)					$ 7,000	$ (1,795,000)