ACQUISITIONS (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010	Aug. 11, 2010 Phase Forward Incorporated [Member]	Jan. 05, 2011 Art Technology Group, Inc. [Member]	Nov. 30, 2011 Pillar Data Systems, Inc. [Member]	Jul. 18, 2011 Pillar Data Systems, Inc. [Member]	Oct. 24, 2011 RightNow Technologies, Inc. [Member]
Acquisitions Proforma [Abstract]
Total revenues	$ 8,792	$ 8,664	$ 17,184	$ 16,291
Net income	2,192	1,840	4,017	3,163
Basic earnings per share	$ 0.43	$ 0.36	$ 0.80	$ 0.63
Diluted earnings per share	$ 0.43	$ 0.36	$ 0.78	$ 0.62
Acquisitions [Line Items]
Total purchase price					736	1,000
Purchase price payable consisting of estimated fair value of the liability for contingent consideration								346
Cash portion of purchase price					735	990
Fair value of stock options and restricted stock-based awards assumed					1	16
Identifiable intangible assets recorded					370	404		142
In-process research and development recorded					20
Net tangible assets (liabilities) assumed					17	50		(10)
Goodwill recorded					329	552		214
Amount of Earn-Out that an affiliate of Mr. Ellison has the first preference right to receive								565
Estimated fair value of the Earn-Out Liability							368
Percentage rights that Mr. Ellison and his affiliates have over any amount of the Earn-Out that exceeds $565 million								55.00%
Amount to be paid in cash per share of common stock upon the consummation of the merger									$ 43
Estimated total purchase price									$ 1,600