Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 19,416
Translation adjustments	$ 103	$ 100	(90)	$ 119
Ending Balance	19,894	18,894	19,894	18,894
Foreign Currency Translation Loss [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(952)	(666)	(759)	(685)
Translation adjustments	103	100	(90)	119
Ending Balance	(849)	(566)	(849)	(566)
Retirement Plans Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	135	232	181	270
Reclassifications from AOCI	(23)	(23)	(69)	(61)
Ending Balance	112	209	112	209
Accumulated Other Comprehensive (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(817)	(434)	(578)	(415)
Ending Balance	$ (737)	$ (357)	$ (737)	$ (357)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss).

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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