Goodwill and Other Intangibles (Detail) - Schedule of other intangible assets not subject to amortization (USD $) In Millions, unless otherwise specified	Nov. 30, 2011	May 31, 2011	Nov. 30, 2010
Indefinite-Lived Intangible Assets	$ 1.8	$ 1.8	$ 1.8
Trademarks and Other [Member]
Indefinite-Lived Intangible Assets	$ 1.8	$ 1.8	$ 1.8

Sum of the carrying amounts (original costs for current and prior period additions adjusted for impairment, if any) as of the balance sheet date of intangible assets, excluding goodwill, having a projected indefinite period of benefit.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6905858&loc=d3e16323-109275

Name:	us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant