ACQUISITIONS - UNAUDITED PRO FORMA FINANCIAL INFORMATION (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Acquisitions Proforma [Abstract]
Total revenues	$ 9,213	$ 9,254	$ 18,045	$ 17,950
Net income	$ 1,920	$ 1,990	$ 3,591	$ 3,537
Basic earnings per share (in dollars per share)	$ 0.47	$ 0.47	$ 0.87	$ 0.83
Diluted earnings per share (in dollars per share)	$ 0.46	$ 0.46	$ 0.85	$ 0.81

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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