CONDENSED CONSOLIDATED STATMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (4,781)	$ (2,541)	$ (13,015)	$ (5,566)
Other comprehensive loss:
Unrealized loss on available-for-sale marketable securities arising during holding period, net of tax benefit of $0	(11)	0	(11)	0
Total comprehensive loss	$ (4,792)	$ (2,541)	$ (13,026)	$ (5,566)