Annual report pursuant to Section 13 and 15(d)

Summary of Warrant Activity (Detail)

v3.22.0.1
Summary of Warrant Activity (Detail) - Warrants - $ / shares
shares in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Dec. 31, 2019
Shares      
Beginning Balance 54,052 2,083 1,933
Granted or Issued   55,864 150
Exercised 35,792 3,862  
Forfeited, cancelled, or expired 407 33  
Ending Balance 17,853 54,052 2,083
Warrants exercisable at December 31, 2021 17,853    
Vested warrants expired during the 12 months ended December 31, 2021 (407)    
Weighted-Average Exercise Price Per Share      
Beginning Balance $ 0.62 $ 6.30 $ 9.65
Granted or Issued   0.42 2.22
Exercised 0.43 0.40  
Forfeited, cancelled, or expired 10.00 20.00  
Ending Balance 0.80 $ 0.62 $ 6.30
Warrants exercisable at December 31, 2021 0.80    
Vested warrants expired during the 12 months ended December 31, 2021 $ 10.00