Stock-Based Compensation (Summary Of Stock Options) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Apr. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Shares, Outstanding, beginning of the year	4,504
Shares, Granted	35
Shares, Exercised	(1,179)
Shares, Forfeited or expired	(237)
Shares, Outstanding, end of the year	3,123
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-Average Exercise Price, Outstanding, beginning of the year (in usd per share)	$ 17.53
Weighted-Average Exercise Price, Granted (in usd per share)	$ 28.26
Weighted-Average Exercise Price, Exercised (in usd per share)	$ 18.15
Weighted-Average Exercise Price, Forfeited or expired (in usd per share)	$ 18.56
Weighted-Average Exercise Price, Outstanding, end of the year (in usd per share)	$ 17.34
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Shares, Exercisable, end of the year	2,317
Shares, Exercisable and expected to vest	3,076
Weighted-Average Exercise Price, Exercisable, end of the year	$ 17.50
Weighted-Average Exercise Price, Exercisable and expected to vest	$ 17.33
Weighted-Average Remaining Contractual Term, Outstanding, end of the year	6 years
Weighted-Average Remaining Contractual Term, Exercisable, end of the year	6 years
Weighted-Average Remaining Contractual Term, Exercisable and expected to vest, years	6 years
Aggregate Intrinsic Value, Outstanding, end of the year	$ 34,655
Aggregate Intrinsic Value, Exercisable, end of the year	25,344
Aggregate Intrinsic Value, Exercisable and expected to vest	$ 34,150

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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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 price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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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 of difference between fair value of the underlying shares reserved for issuance and exercise price of fully vested and expected to vest options that are exercisable.

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The number of exercisable share options (fully vested and expected to vest) that may be converted as of the balance sheet date.

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As of the balance sheet date, the weighted-average exercise price (at which grantees can acquire the shares reserved for issuance) for exercisable 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 that are exercisable or convertible, 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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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Number of share options (or share units) exercised during the current period.

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