Increasing or Decreasing Current Health Care Cost Trend (Detail) - USD ($) $ in Thousands	12 Months Ended
May. 31, 2015	May. 31, 2014
Postretirement Benefits, U.S. Plans
Assumed Health Care Cost Trend Rates, Effect of One Percentage Point Change [Line Items]
1% Increase in trend rate, accumulated benefit obligation	$ 334	$ 239
1% Increase in trend rate, postretirement cost	10	11
1% Decrease in trend rate, accumulated benefit obligation	(290)	(209)
1% Decrease in trend rate, postretirement cost	(8)	(10)
Postretirement Benefits, Non-U.S. Plans
Assumed Health Care Cost Trend Rates, Effect of One Percentage Point Change [Line Items]
1% Increase in trend rate, accumulated benefit obligation	6,430	6,502
1% Increase in trend rate, postretirement cost	675	727
1% Decrease in trend rate, accumulated benefit obligation	(3,295)	(5,011)
1% Decrease in trend rate, postretirement cost	$ (499)	$ (534)

Assumed Health Care Cost Trend Rates, Effect of One Percentage Point Change [Line Items]

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- Definition

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (m)

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

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- Definition

Amount of effect of a one-percentage-point decrease in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the accumulated postretirement benefit obligation for health care benefits.

+ References

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- Definition

The effect of a one-percentage-point increase in the assumed health care cost trend rates on the aggregate of the service and interest cost components of net periodic postretirement health care benefit costs.

+ References

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