XML 38 R50.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Summary of Option Activity Under Company's Equity Incentive Plans (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Number of Shares Underlying Outstanding Options      
Number of Shares Underlying Outstanding Options, Beginning Balance 1,361,977 821,741  
Number of Shares Underlying Outstanding Options, Options granted 450,900 612,050  
Number of Shares Underlying Outstanding Options, Options exercised (41,219) (12,716)  
Number of Shares Underlying Outstanding Options, Options canceled/forfeited (182,722) (43,315)  
Number of Shares Underlying Outstanding Options, Options expired (11,395) (15,783)  
Number of Shares Underlying Outstanding Options, Ending Balance 1,577,541 1,361,977 821,741
Number of Shares Underlying Outstanding Options, Exercisable- December 31, 2019 740,356    
Shares available to be granted - December 31, 2019 1,014,126    
Weighted- Average Exercise Price      
Weighted- Average Exercise Price, Beginning Balance $ 12.04 $ 13.69  
Weighted- Average Exercise Price, Options granted 7.85 13.13  
Weighted- Average Exercise Price, Options exercised 4.57 4.17  
Weighted- Average Exercise Price, Options Canceled/forfeited 8.36 7.76  
Weighted- Average Exercise Price, Options expired 96.49 158.81  
Weighted- Average Exercise Price, Ending Balance 10.85 $ 12.04 $ 13.69
Weighted- Average Exercise Price, Exercisable - December 31, 2018 $ 13.30    
Weighted-Average Remaining Contractual Term (Years)      
Weighted-Average Remaining Contractual Term (Years), Outstanding Balance 8 years 1 month 24 days 8 years 8 months 15 days 9 years 2 months 1 day
Aggregate Intrinsic Value      
Aggregate Intrinsic Value, Outstanding $ 2,294 $ 6,376  
Aggregate Intrinsic Value, Options exercised 159 213  
Aggregate Intrinsic Value, Outstanding $ 1,350 $ 2,294 $ 6,376