CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended								6 Months Ended	9 Months Ended		12 Months Ended
	Aug. 30, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Sales		$ 8,382	$ 7,575	$ 6,649	$ 5,629	$ 5,845	$ 3,672	$ 3,691	$ 3,397	$ 12,278	$ 19,853	$ 10,760	$ 28,235	$ 16,605	$ 10,234
Cost of sales			2,281	1,975	2,066		1,151			4,041	6,322	3,490	9,141	5,779	3,276
Gross profit		5,563	5,294	4,674	3,563	3,556	2,521	2,537	2,212	8,237	13,531	7,270	19,094	10,826	6,958
Other costs and expenses:
Research and development			1,016		730		613			1,618	2,634	1,890	3,731	2,549	1,941
Professional services			2,039	1,661	2,118		628			3,779	5,818	1,815	8,507	3,133	1,769
Salaries and related costs			3,159	3,510	3,488		2,170			6,998	10,157	5,785	14,025	9,272	6,920
Selling, general and administrative			3,836	3,037	2,957		1,898			5,994	9,830	6,221	13,700	9,407	8,689
Severance and related expense						700							0	741	1,524
Total other costs and expenses					9,293		5,309					15,711	39,963	25,102	20,843
Loss from operations					(5,730)		(2,788)					(8,441)	(20,869)	(14,276)	(13,885)
Interest income					423								1,392	616	0
Interest expense													(8)	(104)	(136)
Other losses, net					(295)		(868)			$ (495)	$ (265)	(868)	(351)	(947)	0
Change in fair value of derivative liabilities												20	0	20	183
Total other income, net					128		(763)					(815)	1,033	(415)	47
Loss from continuing operations before income taxes					(5,602)		(3,551)					(9,256)	(19,836)	(14,691)	(13,838)
Income tax benefit					6		(2,408)					(2,384)	(130)	(3,907)	(156)
Net loss from continuing operations		$ (5,433)	$ (4,370)	$ (4,295)	$ (5,608)	$ (3,912)	(1,143)	$ (2,938)	$ (2,791)			(6,872)	(19,706)	(10,784)	(13,682)
Income from discontinued operations, net of tax							540					5,062	0	5,099	8,620
Gain on sale of the Core Business, net of tax	$ 68,404						69,072					69,072	0	68,404	0
Total income from discontinued operations, net of tax							69,612					74,134	0	73,503	8,620
Net income (loss)							$ 68,469					$ 67,262	$ (19,706)	$ 62,719	$ (5,062)
Loss per share from continuing operations
Basic and diluted (in dollars per share)							$ (0.03)					$ (0.21)	$ (0.58)	$ (0.32)	$ (0.44)
Income per share from discontinued operations
Basic (in dollars per share)							2.09					2.25	0.00	2.21	0.27
Diluted (in dollars per share)							1.99					2.19	0.00	2.14	0.27
Income (loss) per share from all operations
Basic (in dollars per share)							2.06					2.04	(0.58)	1.89	(0.16)
Diluted (in dollars per share)							$ 1.96					$ 1.98	$ (0.58)	$ 1.83	$ (0.17)
Weighted average number of shares outstanding basic (in shares)							33,275					33,014	34,069	33,185	31,420
Weighted average number of shares outstanding dilutive (in shares)							34,934					33,952	34,069	34,366	31,427