Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating expenses:
Research and development expenses		$ 6,361
General and administrative expenses	$ 1,935	3,683
Gain on sale of assets	(2,139)
Total operating (income) expenses	(204)	10,044
Income (loss) from operations	204	(10,044)
Other income and expenses:
Interest income	45	365
Interest expense		(478)
Other expense, net		(301)
Total other income and expenses	45	(414)
Net income (loss)	249	(10,458)
Other comprehensive income:
Unrealized gain on marketable securities		9
Other comprehensive income		9
Comprehensive income (loss)	$ 249	$ (10,449)
Net income (loss) per common share - basic and diluted	$ 0.02	$ (0.78)
Weighted-average common shares used to compute basic and diluted net loss per common share	13,380	13,343