Net Loss Per Share - Basic and Diluted (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended
Mar. 31, 2020
Mar. 31, 2019
Numerator:    
Net loss $ (17,759) $ (10,779)
Denominator:    
Weighted averave common shares used for basic and diluted earnings per share (in shares) 22,456,365 20,495,671
Loss per share:    
Basic and diluted (in dollars per share) $ (0.79) $ (0.53)