Income Taxes - Reconciliation of Changes in Gross Balance of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
May 31, 2017	May 31, 2016	May 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, as of the beginning of the period	$ 506	$ 438	$ 506
Gross increases related to prior period tax positions	31	49	32
Gross decreases related to prior period tax positions	(163)	(20)	(123)
Gross increases related to current period tax positions	115	81	82
Gross decreases related to current period tax positions	0	0	(9)
Settlements	(12)	(13)	(27)
Lapse of statute of limitations	(21)	(17)	(10)
Increase due to currency translation	5
Decrease due to currency translation		(12)	(13)
UNRECOGNIZED TAX BENEFITS, AS OF THE END OF THE PERIOD	$ 461	$ 506	$ 438

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=65882285&loc=SL6600010-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Unrecognized Tax Benefit
-URI http://asc.fasb.org/extlink&oid=6527854

+ Details

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Amount of decrease in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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