Annual report pursuant to Section 13 and 15(d)

Stockholders' Equity - Summary of Stock Option Activity (Detail)

v3.20.1
Stockholders' Equity - Summary of Stock Option Activity (Detail) - $ / shares
shares in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]      
Number of Options, Beginning balance 5,385 4,826 3,394
Number of Options, Granted 1,723 943 1,733
Number of Options, Exercised 0 (211) (79)
Number of Options, Forfeited/cancelled/expired (5,809) (173) (222)
Number of Options, Ending balance 1,299 5,385 4,826
Number of Options, Exercisable 1,134    
Weighted-Average Exercise Price, Beginning balance $ 5.20 $ 5.05 $ 5.10
Weighted-Average Exercise Price, Granted 1.84 5.08 4.91
Weighted-Average Exercise Price, Exercised 0.00 1.71 1.32
Weighted-Average Exercise Price, Forfeited/cancelled/expired 4.51 4.83 6.09
Weighted-Average Exercise Price, Ending balance 3.82 $ 5.20 $ 5.05
Weighted-Average Exercise Price, Vested, Exercisable $ 4.29    
Weighted-Average Remaining Contractual Term Outstanding 5 years 2 months 12 days    
Weighted-Average Remaining Contractual Term Exercisable 4 years 6 months