Consolidated Statements of Comprehensive Loss - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (5,812,000)	$ (3,870,000)	$ (6,370,000)
Other comprehensive (loss) income, net:
Unrealized (loss) gain on investments, net	(98,000)	(103,000)	(5,000)
Reclassification of net realized investment (gains) losses included in net loss	164,000	1,000	(6,000)
Foreign currency translation adjustment	77,000	(373,000)	408,000
Total other comprehensive income (loss), net	143,000	(475,000)	397,000
Comprehensive loss	$ (5,669,000)	$ (4,345,000)	$ (5,973,000)