CONDENSED CONSOLIDATED STATMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (5,119)	$ (3,654)	$ (9,222)	$ (8,234)
Other comprehensive income:
Unrealized gain on available-for-sale marketable securities arising during holding period, net of tax benefit of $0	0	0	28	0
Total comprehensive loss	$ (5,119)	$ (3,654)	$ (9,194)	$ (8,234)