Discontinued Operations (Detail) - Schedule of operating results of the discontinued operations (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Revenues	$ 0	$ 9.3	$ 0.1	$ 17.7
Non-cash impairment			(0.9)	(3.4)
Earnings (loss) before income taxes	(0.6)	(1.7)	(4.0)	(6.0)
Income tax benefit (expense)	0.2	0.6	1.1	1.4
Earnings (loss) from discontinued operations, net of tax	$ (0.4)	$ (1.1)	$ (2.9)	$ (4.6)

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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+ Details

- Definition

This element represents the overall income (loss) from a disposal group apportioned to the parent that is classified as a component of the entity, net of income tax, reported as a separate component of income before extraordinary items after deduction or consideration of the amount which may be allocable to noncontrolling interests, if any. Includes the following (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.

+ References+ Details