Net Loss Per Share (Tables)
 12 Months Ended
Dec. 31, 2021
Earnings Per Share [Abstract]  
Computation of Basic and Diluted Net Loss Per Share The following table sets forth the computation of basic and diluted net loss per share (in thousands, except share and per-share data):
 Year Ended December 31,
 202120202019
Numerator:
     Net loss$(25,687)$(68,876)$(55,350)
Denominator:   
     Weighted-average common shares outstanding - basic and diluted114,328,798 101,202,176 45,548,511 
Net loss per share:
     Basic and diluted$(0.22)$(0.68)$(1.22)
Schedule of Potential Common Shares Issuable Upon Conversion of Warrants
The following table represents the potential dilutive common shares excluded from the computation of the diluted net loss per share for all periods presented, as the effect would have been anti-dilutive:
 Year Ended December 31,
 202120202019
Options, RSUs and ESPP shares11,492,002 7,909,583 7,002,527 
Warrants to purchase common stock10,735,980 12,378,016 23,084,120 
Total22,227,982 20,287,599 30,086,647