EMPLOYEE BENEFIT PLANS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		May 31, 2017		May 31, 2016		May 31, 2015
Shares Under Restricted Stock-based Awards [Abstract]
Beginning balance		52		28		1
Granted		42		34		28
Assumed		14
Vested and Issued		(18)		(7)
Canceled		(7)		(3)		(1)
Ending balance		83		52		28
Weighted Average Grant Date Fair Value [Abstract]
Total grant date fair value of restricted stock-based awards, vested and issued		$ 715		$ 261		$ 28
Beginning balance		$ 39.29		$ 40.63		$ 35.29
Granted		39.40		38.50		40.73
Assumed		37.83
Vested and Issued		40.39		40.39
Canceled		39.73		39.73		39.52
Ending balance		$ 39.18		$ 39.29		$ 40.63
Unrecognized compensation expense related to non-vested restricted stock-based awards		$ 2,200
Shares Under Option [Abstract]
Beginning balance		375		413		462
Granted		18	[1]	25	[1]	34
Assumed		2		1		3
Exercised		(77)		(53)		(70)
Canceled		(6)		(11)		(16)
Ending balance		312		375		413
Vested		238
Expected to vest	[2]	68
Total		306
Weighted Average Exercise Price [Abstract]
Beginning balance		$ 29.66		$ 28.64		$ 27.37
Granted		40.90	[1]	40.34	[1]	40.54
Assumed		13.06		4.97		21.98
Exercised		26.65		25.13		24.49
Canceled		36.28		35.19		33.76
Ending balance		29.02		$ 29.66		$ 28.64
Vested		29.02
Expected to vest	[2]	36.92
Total		$ 30.79
Weighted Average Remaining Contract Term (in years) [Abstract]
Vested		4 years 5 months 12 days
Expected to vest	[2]	6 years 8 months 12 days
Total		4 years 11 months 12 days
Aggregate Intrinsic Value (in millions) [Abstract]
Vested	[3]	$ 3,908
Expected to vest	[2],[3]	632
Total	[3]	$ 4,540
Closing stock price		$ 45.39
Unrecognized compensation expense for shares expected to vest		$ 282
Shares not expected to vest		6
Weighted Average Input Assumptions Used and Resulting Fair Values [Abstract]
Expected life (in years)		4 years 9 months 18 days		4 years 9 months 18 days		5 years 1 month 6 days
Risk-free interest rate		1.00%		1.60%		1.70%
Volatility		23.00%		24.00%		23.00%
Dividend yield		1.50%		1.50%		1.20%
Weighted-average fair value per share		$ 8.18		$ 8.49		$ 9.62
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 1,350		$ 1,037		$ 933
Estimated income tax benefit included in provision for income taxes		(423)		(322)		(294)
Total stock-based compensation, net of estimated income tax benefit		$ 927		$ 715		$ 639
Common stock issued under stock purchase plans		3		3		3
Other Postretirement Plans [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total defined benefit plan pension expense		$ 85		$ 95		$ 69
Aggregate projected benefit obligation		1,100		949
Aggregate net liability (funded status)		$ 712		$ 587
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		51
Common stock issued under stock purchase plans		3		3		3
Cloud SaaS [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 23		$ 17		$ 10
Cloud PaaS and IaaS [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		5		4		5
Software license updates and product support [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		26		23		21
Hardware [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		11		12		12
Services business [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		44		29		30
Sales and marketing [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		306		220		180
Research and development [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		770		609		522
General and administrative [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		130		120		148
Acquisition related and other [Member]
Stock-based compensation expense and valuations of stock awards [Abstract]
Total stock-based compensation		$ 35		$ 3		$ 5
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 7 months 10 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 1 month 2 days

[1] Approximately 7 million of the 18 million stock options granted during fiscal 2017 and 7 million of the 25 million stock options granted during fiscal 2016 were to our Chief Executive Officers and Chief Technology Officer and have contractual lives of five years versus the 10-year contractual lives for most of the other stock options granted.

[2] 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, 2017 was approximately $282 million and is expected to be recognized over a weighted-average period of 2.09 years. Approximately 6 million shares outstanding as of May 31, 2017 were not expected to vest.

[3] The aggregate intrinsic value was calculated based on the gross difference between our closing stock price on the last trading day of fiscal 2017 of $45.39 and the exercise prices for all “in-the-money” options outstanding, excluding tax effects.