Stock Based Compensation (Summary Of Restricted Share Activity) (Details) (USD $)	9 Months Ended
Feb. 28, 2015
Stock Based Compensation [Abstract]
Number of Shares, Outstanding, May 31, 2014	245,200
Number of Shares, Granted	91,540
Number of Shares, Vested	(400)
Number of Shares, Forfeited	(1,200)
Number of Shares, Outstanding, February 28, 2015	335,140
Weighted Average Grant Date Fair Value, Outstanding, May 31, 2014	$ 23.71
Weighted Average Grant Date Fair Value, Granted	$ 36.63
Weighted Average Grant Date Fair Value, Vested	$ (23.65)
Weighted Average Grant Date Fair Value, Forfeited	$ (23.65)
Weighted Average Grant Date Fair Value, Outstanding, February 28, 2015	$ 27.24

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

+ References

No definition available.

+ Details

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- Definition

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

+ 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 (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

Number of non-vested options outstanding.

+ References

No definition available.

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- Definition

Number of non-vested options forfeited.

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No definition available.

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- Definition

Weighted average grant-date fair value of non-vested options forfeited.

+ References

No definition available.

+ Details

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- Definition

Weighted average grant-date fair value of non-vested options outstanding.

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No definition available.

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- Definition

Number of options vested.

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No definition available.

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- Definition

Weighted average grant-date fair value of options vested.

+ References

No definition available.

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