Consolidated Statements of Comprehensive Loss Parentheticals - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Consolidated Statements of Operations [Abstract]
Stock-based compensation expense associated with research and development expense	$ 2,176	$ 1,768
Stock-based compensation expense associated with selling, general and administrative expense	$ 2,256	$ 1,643