STOCKHOLDERS' EQUITY (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	$ 327	$ 254	$ 646	$ 507
Sales and marketing [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	68	55	133	107
Cloud software as a service and platform as a service [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	6	4	11	8
Cloud infrastructure as a service [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	1	1	2	2
Software license updates and product support [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	6	6	12	12
Hardware products [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	2	2	4	3
Hardware Support [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	1	1	2	3
Services business [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	9	7	17	14
Research and development [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	188	151	382	298
General and administrative [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	35	27	72	57
Acquisition related and other [Member]
Stock-Based Compensation Expense and Valuations of Stock Awards [Abstract]
Total stock-based compensation	$ 11	$ 0	$ 11	$ 3