This item represents the fair value of equity instruments that were granted but not vested during the period.

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 14

-Section F

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

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-Publisher FASB

-Name Accounting Standards Codification

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-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

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- Definition

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.

+ References

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- Definition

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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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

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

+ References

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- Definition

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

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-Subparagraph (c)(1)(i)-(ii)

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- Definition

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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-Subparagraph (e)(1)

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- Definition

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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-Publisher FASB

-Name Accounting Standards Codification

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- Definition

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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- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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Disclosure of Compensation Related Costs, Share Based Payments (Details) (2009 Stock Incentive Plan, USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended		0 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jun. 06, 2014	Jun. 19, 2013	Jun. 07, 2013	Sep. 13, 2013	Sep. 19, 2014	Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares available for grant	3,893,708
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Grants in period (in shares)	91,000
Allocated share-based compensation expense		$ 4,001
Unrecognized compensation costs related to Plan	6,791
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award
Aggregate intrinsic value for outstanding options	24,238
Weighted average remaining contractual life (in years)	5 years 2 months 23 days
Weighted average exercise price for outstanding shares (in dollars per share)	$ 35.77
Weighted average exercise price for vested options (in dollars per share)	5 years 2 months 23 days
Aggregate intrinsic value for exercised options	11,199
Fair value of vested options during period	6,270
Allocated share-based compensation expense	6,292
Unrecognized compensation costs related to Plan	0
Number of options outstanding	436,515							712,024
Certain Officers and Key Employees \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Grants in period (in shares)			91,000	77,650	77,650
Fair value of awards during period			6,584
Certain Officers and Key Employees \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award
Grants in period (in shares)			30,538
Fair value of awards during period			2,209
Non-Employee Members of the Board \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Grants in period (in shares)						14,000
Non-Employee Members of the Board \| Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award
Grants in period (in shares)							13,955
Fair value of awards during period							$ 990