Share-based Compensation Arrangement By Share Based Payment Award Award Exercises After Grant Term Maximum

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Award Requisite Service Period 1

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period 1

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Award Vesting Period

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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.

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- Definition

Aggregate number of common shares reserved for future issuance.

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- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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- Definition

The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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The total fair value of equity-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices of vested portions of options outstanding and currently exercisable under the option plan as of the balance sheet date.

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The weighted average period between the balance sheet date and expiration for all vested portions of options outstanding and currently exercisable (or convertible) under the plan, which may be expressed in a decimal value for number of years.

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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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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The total dollar difference between fair values of the underlying shares reserved for issuance and exercise prices pertaining to options outstanding under the plan as of the balance sheet date.

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Stock-Based Compensation (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	May 31, 2012	May 31, 2011	May 31, 2010
2005 Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under plan (in shares)	14,000,000
Common Stock, Capital Shares Reserved for Future Issuance (in shares)	8,171,124
Stock-based compensation	$ 20.3	$ 15.2	$ 15.3
The total income tax benefit recognized in the consolidated income statement for share-based compensation arrangements	5.6	4.5	3.9
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term after grant options may be exercised (in years)	10 years
Options vesting period (in years)	10 years
Weighted-average fair value of stock options granted (in dollars per share)	$ 12.08	$ 8.04	$ 8.23
Intrinsic value of options exercised during the period	0.6
Proceeds from Stock Options Exercised	3.3
Fair value of vested stock options	12.9	9.0	6.8
Aggregate intrinsic value of outstanding options	22.4
Aggregate intrinsic value of exercisable options	2.1
The weighted-average remaining contractual term of stock options exercisable (in years)	2.1
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards (in years)	3 years
Unvested Stock Options and Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to unvested stock options and restricted stock	$ 64.4
Weighted average over which stock options and restricted stock costs will be recognized (in years)	3.3
Minimum [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period over which options vest (in years)	3 years
Maximum [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period over which options vest (in years)	10 years