Annual report pursuant to Section 13 and 15(d)

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

v3.5.0.1
Description of Stock Plans - Exercise Price for Options Outstanding and Options Exercisable (Detail)
 12 Months Ended
Mar. 31, 2016
$ / shares
shares
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Options Outstanding (in shares) | shares 7,824,395
Options Exercisable (in shares) | shares 2,943,295
$0.00 - 0.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) $ 0
Range of Exercise Price, upper limit ($ per share) $ 0.50
Options Outstanding (in shares) | shares 8,065
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 0.24
Weighted-Average Remaining Life (Years) 3 years 11 months 27 days
Options Exercisable (in shares) | shares 8,065
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 0.24
$0.51 - 1.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 0.51
Range of Exercise Price, upper limit ($ per share) $ 1.00
Options Outstanding (in shares) | shares 153,071
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 0.65
Weighted-Average Remaining Life (Years) 6 years 3 months 18 days
Options Exercisable (in shares) | shares 149,297
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 0.65
$1.01 - 1.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 1.01
Range of Exercise Price, upper limit ($ per share) $ 1.5
Options Outstanding (in shares) | shares 2,064,650
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 1.38
Weighted-Average Remaining Life (Years) 5 years 18 days
Options Exercisable (in shares) | shares 6,250
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 1.18
$1.51 - 2.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 1.51
Range of Exercise Price, upper limit ($ per share) $ 2
Options Outstanding (in shares) | shares 407,167
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 1.51
Weighted-Average Remaining Life (Years) 9 years 7 months 6 days
Options Exercisable (in shares) | shares 37,500
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 1.51
$2.01 - 2.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 2.01
Range of Exercise Price, upper limit ($ per share) $ 2.50
Options Outstanding (in shares) | shares 253,776
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 2.43
Weighted-Average Remaining Life (Years) 4 years 9 months 29 days
Options Exercisable (in shares) | shares 170,443
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 2.41
$2.51 - 3.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 2.51
Range of Exercise Price, upper limit ($ per share) $ 3.00
Options Outstanding (in shares) | shares 1,214,888
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 2.62
Weighted-Average Remaining Life (Years) 8 years 6 months 4 days
Options Exercisable (in shares) | shares 577,128
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 2.65
$3.51 - 4.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 3.51
Range of Exercise Price, upper limit ($ per share) $ 4.00
Options Outstanding (in shares) | shares 1,626,634
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 3.93
Weighted-Average Remaining Life (Years) 8 years 8 months 1 day
Options Exercisable (in shares) | shares 718,717
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 3.93
$4.01 - 4.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 4.01
Range of Exercise Price, upper limit ($ per share) $ 4.50
Options Outstanding (in shares) | shares 1,566,144
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 4.20
Weighted-Average Remaining Life (Years) 7 years 8 months 5 days
Options Exercisable (in shares) | shares 777,145
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 4.21
$4.51 - 5.00  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of Exercise Price, lower limit ($ per share) 4.51
Range of Exercise Price, upper limit ($ per share) $ 5.00
Options Outstanding (in shares) | shares 60,000
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 4.65
Weighted-Average Remaining Life (Years) 6 years 11 months 27 days
Options Exercisable (in shares) | shares 60,000
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 4.65
$5.01 and over  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Exercise Price ($ per share) $ 5.01
Options Outstanding (in shares) | shares 470,000
Options Outstanding, Weighted Average Exercise Price ($ per share) $ 16.32
Weighted-Average Remaining Life (Years) 2 years 9 months 4 days
Options Exercisable (in shares) | shares 438,750
Options Exercisable, Weighted Average Exercise Price ($ per share) $ 17.06