Annual report pursuant to Section 13 and 15(d)

Description of Stock Plans - Additional Information (Detail)

v3.19.1
Description of Stock Plans - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Mar. 31, 2017
May 23, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Forfeited/Canceled (in shares) 1,553,082      
Weighted average grant date fair value (in dollars per share) $ 1.02 $ 0.94 $ 0.82  
Total unrecognized stock base compensation expense $ 2,639 $ 2,353 $ 5,038  
Unvested stock options, weighted average period 1 year 11 months 10 days 2 years 2 months 12 days 2 years 2 months 12 days  
Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Option plan, term 10 years      
Stock Option        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Granted (in shares) 1,463,925 1,963,378 4,271,523  
Forfeited/Canceled (in shares) 1,552,192 1,698,906    
Restricted Stock        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Number of shares granted (in shares) 539,213      
Stock Option Plan 2011        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Reserved for future issuance (in shares)       20,000,000
Available for issuance (in shares) 8,685,457 9,135,513    
Stock Incentive Plans | Minimum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Option plan, term 3 years      
Stock Incentive Plans | Maximum        
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]        
Option plan, term 4 years