Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net loss	$ (13,040)	$ (25,573)
Other comprehensive income:
Unrealized gain on available-for-sale securities	4	152
Reclassification of realized gains included in net loss	(73)	(135)
Comprehensive loss	$ (13,109)	$ (25,556)