Quarterly report pursuant to Section 13 or 15(d)

Description of Stock Plans - Summary of Exercise Price (Details)

v3.10.0.1
Description of Stock Plans - Summary of Exercise Price (Details)
 9 Months Ended
Dec. 31, 2018
$ / shares
shares
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Options Outstanding, Number of Shares (in shares) | shares 9,535,775
Options Exercisable, Number of Shares (in shares) | shares 5,007,381
$0.00 - 0.50  
Employee Stock Ownership Plan E S O P Disclosures [Line Items]  
Range of exercise price, lower limit (in dollars per share) $ 0
Range of exercise price, upper limit (in dollars per share) $ 0.50
Options Outstanding, Number of Shares (in shares) | shares 6,204
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 0.24
Options Outstanding, Weighted Average Remaining Life 1 year 2 months 23 days
Options Exercisable, Number of Shares (in shares) | shares 6,204
Options Exercisable, Weighted Average Exercise Price (in dollars 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 (in dollars per share) 0.51
Range of exercise price, upper limit (in dollars per share) $ 1.00
Options Outstanding, Number of Shares (in shares) | shares 2,644,713
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 0.73
Options Outstanding, Weighted Average Remaining Life 7 years 10 months 2 days
Options Exercisable, Number of Shares (in shares) | shares 674,480
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 0.74
$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, Number of Shares (in shares) | shares 2,595,393
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 1.28
Options Outstanding, Weighted Average Remaining Life 7 years 6 months 25 days
Options Exercisable, Number of Shares (in shares) | shares 1,591,672
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 1.27
$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, Number of Shares (in shares) | shares 1,465,698
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 1.65
Options Outstanding, Weighted Average Remaining Life 9 years 29 days
Options Exercisable, Number of Shares (in shares) | shares 408,223
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 1.60
$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, Number of Shares (in shares) | shares 589,767
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 2.18
Options Outstanding, Weighted Average Remaining Life 9 years 1 month 13 days
Options Exercisable, Number of Shares (in shares) | shares 92,802
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 2.04
$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, Number of Shares (in shares) | shares 798,200
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 2.61
Options Outstanding, Weighted Average Remaining Life 5 years 7 months 2 days
Options Exercisable, Number of Shares (in shares) | shares 798,200
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 2.61
$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, Number of Shares (in shares) | shares 732,800
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 3.96
Options Outstanding, Weighted Average Remaining Life 5 years 8 months 21 days
Options Exercisable, Number of Shares (in shares) | shares 732,800
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 3.96
$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, Number of Shares (in shares) | shares 593,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 4.14
Options Outstanding, Weighted Average Remaining Life 5 years 10 months 18 days
Options Exercisable, Number of Shares (in shares) | shares 593,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 4.14
$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, Number of Shares (in shares) | shares 60,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 4.65
Options Outstanding, Weighted Average Remaining Life 4 years 2 months 27 days
Options Exercisable, Number of Shares (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, Number of Shares (in shares) | shares 50,000
Options Outstanding, Weighted Average Exercise Price (in dollars per share) $ 5.89
Options Outstanding, Weighted Average Remaining Life 5 years 8 months 12 days
Options Exercisable, Number of Shares (in shares) | shares 50,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share) $ 5.89