Annual report pursuant to Section 13 and 15(d)

Description of Stock Plans - Summary of Options Granted under all Equity Plans (Detail)

v3.19.1
Description of Stock Plans - Summary of Options Granted under all Equity Plans (Detail) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
Number of Shares      
Forfeited/Canceled (in shares) (1,553,082)    
Stock Option      
Number of Shares      
Beginning Balance (in shares) 9,741,969 9,735,778  
Granted (in shares) 1,463,925 1,963,378 4,271,523
Forfeited/Canceled (in shares) (1,552,192) (1,698,906)  
Exercised (in shares) (524,817) (258,281)  
Ending Balance (in shares) 9,128,885 9,741,969 9,735,778
Vested and expected to vest (in shares) 8,147,149    
Exercisable (in shares) 5,800,564    
Weighted Average Exercise Price (per share)      
Beginning Balance (in dollars per share) $ 2.08 $ 2.56  
Granted (in dollars per share) 1.69 1.53  
Forfeited/Canceled (in dollars per share) 3.72 4.40  
Exercised (in dollars per share) 0.94 1.04  
Ending Balance (in dollars per share) 1.80 $ 2.08 $ 2.56
Vested and expected to vest (net of estimated forfeitures) (in dollars per share) 1.86    
Exercisable (in dollars per share) $ 2.06    
Weighted Average Remaining Contractual Life (in years)      
Outstanding 7 years 3 months 21 days 7 years 9 months 25 days 7 years 11 months 13 days
Vested and expected to vest (net of estimated forfeitures) 7 years 2 months 5 days    
Exercisable, March 31, 2019 6 years 9 months    
Aggregate Intrinsic Value (in thousands)      
Balance $ 16,347 $ 6,286 $ 801
Vested and expected to vest (net of estimated forfeitures) 14,224    
Exercisable, March 31, 2019 $ 9,237