STOCKHOLDERS' EQUITY (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	$ 397	$ 396	$ 843	$ 832
Cloud services and license support [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	30	24	61	48
Hardware [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	3	2	6	5
Services [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	14	12	28	25
Sales and marketing [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	37	93	125	188
Research and development [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	272	222	543	479
General and administrative [Member]
Stock-Based Compensation Expense and Stock Awards [Abstract]
Total stock-based compensation	$ 41	$ 43	$ 80	$ 87