Plan Assets for Defined Benefit Plan (Detail)	May. 31, 2015	May. 31, 2014
Asset category
Weighted-average asset allocation	100.00%	100.00%
Equity Securities
Asset category
Weighted-average asset allocation	53.00%	52.00%
Debt Securities
Asset category
Weighted-average asset allocation	41.00%	44.00%
Other securities
Asset category
Weighted-average asset allocation	6.00%	4.00%

Percentage of fair value of investments (categorized by debt securities, equity securities, real estate and other plan assets) to the fair value of plan assets held.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

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Data Type:	num:percentItemType
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