Income Taxes - Reconciliation of Changes in Gross Balance of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions	12 Months Ended
May 31, 2018	May 31, 2017	May 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, as of the beginning of the period	$ 461	$ 506	$ 438
Gross increases related to prior period tax positions	19	31	49
Gross decreases related to prior period tax positions	(12)	(163)	(20)
Gross increases related to current period tax positions	249	115	81
Settlements	0	(12)	(13)
Lapse of statute of limitations	(20)	(21)	(17)
Increase due to currency translation	1	5
Decrease due to currency translation			(12)
UNRECOGNIZED TAX BENEFITS, AS OF THE END OF THE PERIOD	$ 698	$ 461	$ 506

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=84230637&loc=SL6600010-109319

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Amount of decrease in unrecognized tax benefits resulting from foreign currency translation.

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15A
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-URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319

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

+ 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)(3)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319

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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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