Discontinued Operations (Detail) - Schedule of operating results of the discontinued operations (USD $) In Millions, unless otherwise specified	3 Months Ended
Aug. 31, 2012	Aug. 31, 2011
Revenues	$ 0	$ 0.1
Non-cash impairment		0.9
Earnings (loss) before income taxes	(0.1)	(2.6)
Income tax benefit (expense)	0	0.6
Earnings (loss) from discontinued operations, net of tax	$ (0.1)	$ (2.0)

Overall income (loss) from a disposal group that is classified as a component of the entity, before income tax, reported as a separate component of income before extraordinary items. Includes the following (before income tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Tax effect allocated to a disposal group that is classified as a component of the entity reported as a separate component of income before extraordinary items. Includes the tax effects of the following: income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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- Definition

Amount of income (loss) from a disposal group, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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