Annual report pursuant to Section 13 and 15(d)

Summary of Warrant Activity (Detail)

v3.20.1
Summary of Warrant Activity (Detail) - Warrants - $ / shares
shares in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Shares      
Beginning Balance 1,933 1,225 2,281
Granted/Issued 150 760 785
Exercised    
Forfeited, cancelled, or expired   (52) (1,841)
Ending Balance 2,083 1,933 1,225
Warrants exercisable, December 31, 2019 2,083    
Weighted-Average Exercise Price Per Share      
Beginning Balance $ 9.65 $ 9.65 $ 20.90
Granted/Issued 2.22 2.23 9.00
Exercised    
Forfeited, cancelled, or expired   2.36 20.00
Ending Balance 6.30 $ 9.65 $ 9.65
Warrants exercisable, December 31, 2019 $ 6.12