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Weighted-Average Assumptions used to Determine Benefit Obligations and Net Periodic Postretirement Cost (Detail) | 12 Months Ended
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May 31, 2017 | May 31, 2016 | May 31, 2015
Postretirement Benefits, U.S. Plans |  |  |
Health Care Cost Trend Rates Assumptions [Line Items] |  |  |
Year-End Benefit Obligations, Discount rate | 3.61% | 3.76% |
Year-End Benefit Obligations, Current healthcare cost trend rate | 14.75% | 10.37% |
Year-End Benefit Obligations, Ultimate healthcare cost trend rate | 4.36% | 4.36% |
Year-End Benefit Obligation, Year ultimate healthcare cost trend rate will be realized | 2037 | 2037 |
Net Periodic Postretirement Cost, Discount rate | 3.76% | 3.95% | 4.00%
Net Periodic Postretirement Cost, Healthcare cost trend rate | 10.37% | 11.34% | 12.28%
Net Periodic Postretirement Cost, Ultimate healthcare cost trend rate | 4.36% | 4.50% | 4.50%
Net Periodic Postretirement Cost, Year ultimate healthcare cost trend rate will be realized | 2037 | 2029 | 2029
Postretirement Benefits, Non-U.S. Plans |  |  |
Health Care Cost Trend Rates Assumptions [Line Items] |  |  |
Year-End Benefit Obligations, Discount rate | 3.61% | 3.92% |
Year-End Benefit Obligations, Current healthcare cost trend rate | 5.85% | 5.98% |
Year-End Benefit Obligations, Ultimate healthcare cost trend rate | 4.20% | 4.20% |
Year-End Benefit Obligation, Year ultimate healthcare cost trend rate will be realized | 2030 | 2030 |
Net Periodic Postretirement Cost, Discount rate | 3.92% | 4.00% | 4.40%
Net Periodic Postretirement Cost, Healthcare cost trend rate | 5.98% | 6.06% | 6.31%
Net Periodic Postretirement Cost, Ultimate healthcare cost trend rate | 4.20% | 4.20% | 4.20%
Net Periodic Postretirement Cost, Year ultimate healthcare cost trend rate will be realized | 2030 | 2030 | 2030

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- Definition Defined benefit plan year ultimate healthcare realized cost trend rate. + References No definition available. + Details
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- Definition The interest rate used to adjust for the time value of money for the plan. + 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 (k)(1) -URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920 + Details
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