EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		May 31, 2019		May 31, 2018		May 31, 2017
Shares Under Restricted Stock-based Awards [Abstract]
Beginning balance		89		83		52
Granted		53		44		42
Assumed						14
Vested and Issued		(31)		(27)		(18)
Canceled		(12)		(11)		(7)
Ending balance		99		89		83
Weighted Average Grant Date Fair Value [Abstract]
Total grant date fair value of restricted stock-based awards, vested and issued		$ 1,300		$ 1,000		$ 715
Beginning balance		$ 42.93		$ 39.18		$ 39.29
Granted		42.47		47.42		39.40
Assumed						37.83
Vested and Issued		41.85		39.10		40.39
Canceled		42.97		41.97		39.73
Ending balance		$ 43.01		$ 42.93		$ 39.18
Unrecognized compensation expense related to non-vested restricted stock-based awards		$ 2,800
Shares Under Stock Option [Abstract]
Beginning balance		304		312		375
Granted		7	[1]	77	[2]	18	[2]
Assumed						2
Exercised		(72)		(78)		(77)
Canceled		(17)		(7)		(6)
Ending balance		222		304		312
Vested		146
Expected to vest	[3]	42
Total		188
Weighted Average Exercise Price [Abstract]
Beginning balance		$ 36.11		$ 29.02		$ 29.66
Granted		43.47	[1]	50.95	[2]	40.90	[2]
Assumed						13.06
Exercised		28.32		28.78		26.65
Canceled		49.28		45.70		36.28
Ending balance		37.78		$ 36.11		$ 29.02
Vested		32.13
Expected to vest	[3]	46.95
Total		$ 35.45
Weighted Average Remaining Contract Term (in years) [Abstract]
Vested		3 years 3 months 25 days
Expected to vest	[3]	6 years 5 months 19 days
Total		4 years 7 days
Aggregate Intrinsic Value (in millions) [Abstract]
Vested	[4]	$ 2,698
Expected to vest	[3],[4]	181
Total	[4]	$ 2,879
Closing stock price		$ 50.60
Unrecognized compensation expense for shares expected to vest		$ 254
Shares not expected to vest		34
Weighted Average Input Assumptions Used and Resulting Fair Values [Abstract]
Expected life (in years)		4 years 7 months 6 days		4 years 8 months 12 days		4 years 9 months 18 days
Risk-free interest rate		2.70%		2.00%		1.00%
Volatility		24.00%		22.00%		23.00%
Dividend yield		1.70%		1.50%		1.50%
Weighted-average fair value per share		$ 10.77		$ 9.34		$ 8.18
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 1,653		$ 1,607		$ 1,350
Estimated income tax benefit included in provision for income taxes		(358)		(451)		(423)
Total stock-based compensation, net of estimated income tax benefit		$ 1,295		$ 1,156		$ 927
Common stock issued under stock purchase plans		2		3		3
Other Postretirement Plans [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total defined benefit plan pension expense		$ 90		$ 102		$ 85
Aggregate projected benefit obligation		1,200		1,100
Aggregate net liability (funded status)		$ 821		$ 711
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 of common stock available for future awards		46
Common stock issued under stock purchase plans		2		3		3
Cloud services and license support [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 99		$ 82		$ 54
Hardware [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		10		10		11
Services [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		49		52		44
Sales and marketing [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		360		361		306
Research and development [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		963		921		770
General and administrative [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		172		180		130
Acquisition related and other [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 0		$ 1		$ 35
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 4 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		2 years 8 months 26 days
Performance-based stock options [Member]
Weighted Average Input Assumptions Used and Resulting Fair Values [Abstract]
Expected life (in years)				7 years
Risk-free interest rate				2.14%
Volatility				22.44%
Dividend yield				1.49%
Weighted-average fair value per share				$ 10

[1] Awards granted in fiscal 2018 included 66.5 million PSOs granted in total to our Chief Executive Officers, Chief Technology Officer, and former President, Product Development, the contractual terms of which are described in greater detail above.

[2] 6.75 million SOs were granted in total during fiscal 2017 to our Chief Executive Officers and Chief Technology Officer and have contractual lives of five years versus the ten-year contractual lives for most of the other SOs granted.

[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, 2019 was approximately $254 million and is expected to be recognized over a weighted-average period of 2.74 years. Approximately 34 million shares outstanding as of May 31, 2019 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 2019 of $50.60 and the exercise prices for all “in-the-money” options outstanding, excluding tax effects.