CONDENSED CONSOLIDATED STATEMENTS 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	$ (8,269)	$ (19,792)	$ (12,974)	$ (22,636)
Other comprehensive loss:
Unrealized gain on investments	84	35	125	38
Comprehensive loss	$ (8,185)	$ (19,757)	$ (12,849)	$ (22,598)