EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		May 31, 2020		May 31, 2019	May 31, 2018
Shares Under Restricted Stock-based Awards [Abstract]
Beginning balance		99		89	83
Granted		50		53	44
Vested and Issued		(34)		(31)	(27)
Canceled		(14)		(12)	(11)
Ending balance		101		99	89
Weighted Average Grant Date Fair Value [Abstract]
Total grant date fair value of restricted stock-based awards, vested and issued		$ 1,500		$ 1,300	$ 1,000
Beginning balance		$ 43.01		$ 42.93	$ 39.18
Granted		53.38		42.47	47.42
Vested and Issued		42.67		41.85	39.10
Canceled		46.81		42.97	41.97
Ending balance		$ 48.36		$ 43.01	$ 42.93
Unrecognized compensation expense related to non-vested restricted stock-based awards		$ 3,200
Shares Under Stock Option [Abstract]
Beginning balance		222		304	312
Granted		0	[1]	7	77	[2]
Exercised		(44)		(72)	(78)
Canceled		(2)		(17)	(7)
Ending balance		176		222	304
Vested		113
Expected to vest	[3]	14
Total		127
Weighted Average Exercise Price [Abstract]
Beginning balance		$ 37.78		$ 36.11	$ 29.02
Granted		0	[1]	43.47	50.95	[2]
Exercised		33.18		28.32	28.78
Canceled		44.76		49.28	45.70
Ending balance		38.86		$ 37.78	$ 36.11
Vested		32.70
Expected to vest	[3]	46.59
Total		$ 34.20
Weighted Average Remaining Contract Term (in years) [Abstract]
Vested		2 years 6 months 10 days
Expected to vest	[3]	6 years 6 months 25 days
Total		2 years 11 months 19 days
Aggregate Intrinsic Value (in millions) [Abstract]
Vested	[4]	$ 2,392
Expected to vest	[3],[4]	99
Total	[4]	$ 2,491
Closing stock price		$ 53.77
Unrecognized compensation expense for shares expected to vest		$ 64
Shares not expected to vest		49
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 1,590		$ 1,653	$ 1,607
Estimated income tax benefit included in provision for income taxes		(343)		(358)	(451)
Total stock-based compensation, net of estimated income tax benefit		$ 1,247		$ 1,295	$ 1,156
Common stock issued under stock purchase plans		2		2	3
Other Postretirement Plans [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total defined benefit plan pension expense		$ 97		$ 90	$ 102
Aggregate projected benefit obligation		1,300		1,200
Aggregate net liability (funded status)		$ 884		$ 821
Employee Stock Purchase Plan [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Stock purchase price as a percentage of the fair market value on the purchase date		95.00%
Shares reserved for future issuances under the purchase plan		44
Common stock issued under stock purchase plans		2		2	3
Cloud services and license support [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 110		$ 99	$ 82
Hardware [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		11		10	10
Services [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		54		49	52
Sales and marketing [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		261		360	361
Research and development [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		1,035		963	921
General and administrative [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		119		$ 172	180
Acquisition related and other [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 0			$ 1
Restricted Stock Units [Member]
Weighted Average Grant Date Fair Value [Abstract]
Weighted average recognition period of unrecognized compensation expense for shares expected to vest		2 years 8 months 19 days
Employee Stock Options [Member]
Weighted Average Grant Date Fair Value [Abstract]
Weighted average recognition period of unrecognized compensation expense for shares expected to vest		1 year 11 months 8 days

[1] Awards granted in fiscal 2018 included 66.5 million PSOs granted in total to certain executive officers, the contractual terms of which are described in greater detail above.

[2] Awards granted in fiscal 2018 included 66.5 million PSOs granted in total to certain executive officers, the contractual terms of which are described in greater detail above

[3] The unrecognized compensation expense calculated under the fair value method for shares expected to vest (unvested shares net of expected forfeitures) as of May 31, 2020 was approximately $64 million and is expected to be recognized over a weighted-average period of 1.94 years. Approximately 49 million shares outstanding as of May 31, 2020 were not expected to vest.

[4] The aggregate intrinsic value was calculated based on the gross difference between our closing stock price on the last trading day of fiscal 2020 of $53.77 and the exercise prices for all “in-the-money” options outstanding, excluding tax effects.