v3.5.0.1

Stockholders Equity - Summary of Stock Options (Details) | 12 Months Ended
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Apr. 30, 2016 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | $ 0.16
Stock option plans, exercise price range, upper limit | $ 18.67
Number of outstanding options | shares | 6,688,200
Weighted average exercise price of outstanding options | $ 6.64
Weighted average remaining contractual term of outstanding options | 6 years 5 months 5 days
Number of exercisable options | shares | 3,004,111
Weighted average exercise price of exercisable options | $ 8.04
Range One [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 0.16
Stock option plans, exercise price range, upper limit | $ 3.03
Number of outstanding options | shares | 392,937
Weighted average exercise price of outstanding options | $ 2.35
Weighted average remaining contractual term of outstanding options | 3 years 2 months 24 days
Number of exercisable options | shares | 332,937
Weighted average exercise price of exercisable options | $ 2.23
Range Two [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 3.15
Stock option plans, exercise price range, upper limit | $ 3.15
Number of outstanding options | shares | 990,000
Weighted average exercise price of outstanding options | $ 3.15
Weighted average remaining contractual term of outstanding options | 6 years 10 months 3 days
Number of exercisable options | shares | 0
Weighted average exercise price of exercisable options | $ 0.00
Range Three [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 3.42
Stock option plans, exercise price range, upper limit | $ 4.86
Number of outstanding options | shares | 734,387
Weighted average exercise price of outstanding options | $ 4.36
Weighted average remaining contractual term of outstanding options | 7 years 2 months 24 days
Number of exercisable options | shares | 254,387
Weighted average exercise price of exercisable options | $ 4.69
Range Four [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 4.87
Stock option plans, exercise price range, upper limit | $ 6.28
Number of outstanding options | shares | 261,911
Weighted average exercise price of outstanding options | $ 5.49
Weighted average remaining contractual term of outstanding options | 8 years 5 months 27 days
Number of exercisable options | shares | 112,327
Weighted average exercise price of exercisable options | $ 5.44
Range Five [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 6.42
Stock option plans, exercise price range, upper limit | $ 6.42
Number of outstanding options | shares | 1,196,400
Weighted average exercise price of outstanding options | $ 6.42
Weighted average remaining contractual term of outstanding options | 8 years 9 months 7 days
Number of exercisable options | shares | 0
Weighted average exercise price of exercisable options | $ 0.00
Range Six [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 6.54
Stock option plans, exercise price range, upper limit | $ 7.36
Number of outstanding options | shares | 788,373
Weighted average exercise price of outstanding options | $ 6.96
Weighted average remaining contractual term of outstanding options | 7 years 4 months 3 days
Number of exercisable options | shares | 523,263
Weighted average exercise price of exercisable options | $ 6.89
Range Seven [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 7.39
Stock option plans, exercise price range, upper limit | $ 7.53
Number of outstanding options | shares | 756,475
Weighted average exercise price of outstanding options | $ 7.47
Weighted average remaining contractual term of outstanding options | 4 years 3 months 7 days
Number of exercisable options | shares | 489,204
Weighted average exercise price of exercisable options | $ 7.46
Range Eight [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 7.6
Stock option plans, exercise price range, upper limit | $ 9.51
Number of outstanding options | shares | 892,709
Weighted average exercise price of outstanding options | $ 9.18
Weighted average remaining contractual term of outstanding options | 6 years 9 months 11 days
Number of exercisable options | shares | 635,401
Weighted average exercise price of exercisable options | $ 9.21
Range Nine [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 9.52
Stock option plans, exercise price range, upper limit | $ 15.12
Number of outstanding options | shares | 639,808
Weighted average exercise price of outstanding options | $ 12.60
Weighted average remaining contractual term of outstanding options | 2 years 7 months 10 days
Number of exercisable options | shares | 621,392
Weighted average exercise price of exercisable options | $ 12.61
Range Ten [Member] |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] |
Stock option plans, exercise price range, lower limit | 18.67
Stock option plans, exercise price range, upper limit | $ 18.67
Number of outstanding options | shares | 35,200
Weighted average exercise price of outstanding options | $ 18.67
Weighted average remaining contractual term of outstanding options | 5 years 11 months 5 days
Number of exercisable options | shares | 35,200
Weighted average exercise price of exercisable options | $ 18.67

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- Definition The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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