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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Unrecognized cost of unvested share-based compensation awards.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of options vested.

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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.

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The ceiling 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.

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Note 5 - Preferred and Common Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			0 Months Ended				1 Months Ended		0 Months Ended						1 Months Ended	24 Months Ended			12 Months Ended		1 Months Ended
	Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012	Jun. 08, 2012 Restricted Stock Units (RSUs) [Member] Certain Employee [Member]	Jun. 10, 2011 Restricted Stock Units (RSUs) [Member] Certain Employee [Member]	Jun. 19, 2013 Restricted Stock Units (RSUs) [Member] Certain Officer And Key Employee [Member]	Jun. 07, 2013 Restricted Stock Units (RSUs) [Member] Certain Officer And Key Employee [Member]	Jun. 19, 2013 Restricted Stock Units (RSUs) [Member] Certain Officer And Key Employee [Member]	Jun. 23, 2011 Restricted Stock Units (RSUs) [Member] Chief Executive Officer [Member]	Sep. 16, 2011 Restricted Stock Units (RSUs) [Member] Non-Employee [Member]	Sep. 13, 2013 Restricted Stock Units (RSUs) [Member] Non Employee Members Of The Board [Member]	Sep. 14, 2012 Restricted Stock Units (RSUs) [Member] Non Employee Members Of The Board [Member]	Apr. 30, 2014 Stock Options [Member]	Apr. 30, 2014 Restricted Stock Units (RSUs) [Member]	Apr. 30, 2014 Series A Preferred Stock [Member]	Jun. 23, 2011 Stock Options [Member]	Apr. 30, 2014 Stock Options [Member]	Apr. 30, 2014 2009 Stock Incentive Plan [Member]	Apr. 30, 2014 Director Stock Plan [Member]	Apr. 30, 2014 Minimum [Member]	Apr. 30, 2014 Maximum [Member]	Jun. 23, 2011 Certain Officer And Key Employee [Member]
Note 5 - Preferred and Common Stock (Details) [Line Items]
Preferred Stock, Shares Authorized	1,000,000														250,000
Preferred Stock, Shares Issued	0	0
Common Stock, Shares Authorized	120,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant																		4,153,608	200,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	712,024	712,024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures				32,998	9,198	77,650	76,150	1,500	15,000	14,000	14,000	14,000										441,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in Dollars per share)				$ 59.48	$ 40.49		$ 62.26	$ 60.47	$ 44.39	$ 47.59	$ 71.02	$ 58.93				$ 14.65
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period																				3 years	5 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value (in Dollars)	$ 22,737
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	6 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number	284,024
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Exercise Price (in Dollars per share)	$ 25.18
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term	4 years 146 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Aggregate Intrinsic Value (in Dollars)	12,349
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value (in Dollars)	2,952
Share-based Compensation (in Dollars)	5,600	4,270	3,792
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized (in Dollars)													$ 325	$ 4,036
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit (in Dollars per share)																	$ 17.64
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit (in Dollars per share)																	$ 44.39