Annual report pursuant to Section 13 and 15(d)

Description of Stock Plans - Exercise Price for Options Outstanding and Options Exercisable (Detail)

v3.20.1
Description of Stock Plans - Exercise Price for Options Outstanding and Options Exercisable (Detail)
 12 Months Ended
Mar. 31, 2020
$ / shares
shares
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Options Outstanding (in shares) | shares 8,984,430
Options Exercisable (in shares) | shares 5,377,389
$0.51 - 1.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) $ 0.51
Range of Exercise Price, upper limit (in dollars per share) $ 1.00
Options Outstanding (in shares) | shares 1,539,065
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 0.73
Weighted-Average Remaining Life (Years) 6 years 7 months 7 days
Options Exercisable (in shares) | shares 826,195
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 0.73
$1.01 - 1.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 1.01
Range of Exercise Price, upper limit (in dollars per share) $ 1.5
Options Outstanding (in shares) | shares 1,839,036
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 1.29
Weighted-Average Remaining Life (Years) 6 years 4 months 7 days
Options Exercisable (in shares) | shares 1,739,744
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 1.30
$1.51 - 2.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 1.51
Range of Exercise Price, upper limit (in dollars per share) $ 2
Options Outstanding (in shares) | shares 969,494
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 1.67
Weighted-Average Remaining Life (Years) 8 years 21 days
Options Exercisable (in shares) | shares 545,113
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 1.66
$2.01 - 2.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 2.01
Range of Exercise Price, upper limit (in dollars per share) $ 2.50
Options Outstanding (in shares) | shares 548,972
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 2.23
Weighted-Average Remaining Life (Years) 8 years 21 days
Options Exercisable (in shares) | shares 293,356
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 2.21
$2.51 - 3.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 2.51
Range of Exercise Price, upper limit (in dollars per share) $ 3.00
Options Outstanding (in shares) | shares 535,958
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 2.59
Weighted-Average Remaining Life (Years) 4 years 1 month 2 days
Options Exercisable (in shares) | shares 535,958
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 2.59
$3.51 - 4.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 3.51
Range of Exercise Price, upper limit (in dollars per share) $ 4.00
Options Outstanding (in shares) | shares 1,763,300
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 3.89
Weighted-Average Remaining Life (Years) 7 years 10 months 7 days
Options Exercisable (in shares) | shares 764,985
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 3.93
$4.01 - 4.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 4.01
Range of Exercise Price, upper limit (in dollars per share) $ 4.50
Options Outstanding (in shares) | shares 475,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 4.13
Weighted-Average Remaining Life (Years) 4 years 6 months 15 days
Options Exercisable (in shares) | shares 475,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 4.13
$4.51 - 5.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit (in dollars per share) 4.51
Range of Exercise Price, upper limit (in dollars per share) $ 5.00
Options Outstanding (in shares) | shares 60,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 4.65
Weighted-Average Remaining Life (Years) 2 years 11 months 27 days
Options Exercisable (in shares) | shares 60,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 4.65
$5.01 and over  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Exercise Price (in dollars per share) $ 5.01
Options Outstanding (in shares) | shares 1,253,605
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 6.29
Weighted-Average Remaining Life (Years) 9 years 6 months 22 days
Options Exercisable (in shares) | shares 137,038
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 6.14