Consolidated Statements of Comprehensive Loss Parentheticals - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Consolidated Statements of Operations [Abstract]
Stock-based compensation expense associated with research and development expense	$ 1,286	$ 2,176
Stock-based compensation expense associated with selling, general and administrative expense	$ 1,565	$ 2,256