EMPLOYEE BENEFIT PLANS Continued (Details)	12 Months Ended
	May 31, 2018 Tranche ExecutiveOfficer shares		May 31, 2017 shares		May 31, 2016 shares		May 31, 2014 shares	May 31, 2013 shares	May 31, 2011 shares	May 31, 2015 shares
Stock-based Payment Award [Line Items]
Options outstanding	304,000,000		312,000,000		375,000,000					413,000,000
Options outstanding vested	201,000,000
Restricted stock-based awards outstanding	89,000,000		83,000,000		52,000,000					28,000,000
Stock options outstanding	43,000,000
Restricted stock-based awards granted (in shares)	44,000,000		42,000,000		34,000,000
Restricted stock-based awards vested (in shares)	27,000,000		18,000,000		7,000,000
Stock options granted	77,000,000	[1]	18,000,000	[2]	25,000,000	[2]
Performance-based restricted stock units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding	1,600,000
Restricted stock-based awards granted (in shares)			2,000,000		2,000,000
Restricted stock-based awards vested (in shares)	2,400,000
Minimum percentage for performance metric	0.00%
Maximum percentage that can exceed target performance metric	150.00%
Performance-based stock options [Member]
Stock-based Payment Award [Line Items]
Expiration period	8 years
Number of vesting tranches granted that potentially may vest | Tranche	7
Number of tranches vests on attainment of market-based metric | Tranche	1
Number of vesting tranches require attainment of both a performance and a market condition | Tranche	6
Award performance period	5 years
Award service period for performance-based metrics, minimum	3 years
Award service period for performance-based metrics, maximum	5 years
Award service period for market-based metric	3 years
Performance-based stock options [Member] | Executive Officers [Member]
Stock-based Payment Award [Line Items]
PSOs granted to number of executive officers | ExecutiveOfficer	4
Service-based stock options [Member]
Stock-based Payment Award [Line Items]
Expiration period	10 years
Chief Technology Officer and Chief Executive Officers [Member]
Stock-based Payment Award [Line Items]
Expiration period	5 years
Stock options granted			7,000,000		7,000,000
Chief Executive Officers, Chief Technology Officer and President, Product Development [Member]
Stock-based Payment Award [Line Items]
Stock options granted	69,000,000
2000 Plan [Member]
Stock-based Payment Award [Line Items]
Increase in number of authorized shares of stock that may be issued	330,000,000						305,000,000		388,313,015
Vesting percentage	25.00%
Vesting period	4 years
Expiration period	10 years
Options outstanding	231,000,000
Options outstanding vested	197,000,000
Shares of common stock available for future awards	376,000,000
2000 Plan [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding	83,000,000
Equivalent number of shares deducted against share pool (in actual number of shares)	2.5
2000 Plan [Member] | Performance-based restricted stock units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding	3,000,000
2000 Plan [Member] | Employee Stock Options [Member]
Stock-based Payment Award [Line Items]
Stock options outstanding	69,000,000
Directors' Plan [Member]
Stock-based Payment Award [Line Items]
Increase in number of authorized shares of stock that may be issued								2,000,000
Vesting period	4 years
Expiration period	10 years
Options outstanding	1,000,000
Options outstanding vested	1,000,000
Shares of common stock available for future awards	1,000,000
Directors' Plan [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding	109,000
Acquired plans [Member]
Stock-based Payment Award [Line Items]
Options outstanding	3,000,000
Acquired plans [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding	3,000,000

[1] Awards granted in fiscal 2018 included 69 million PSOs granted in total to our Chief Executive Officers, Chief Technology Officer, and President, Product Development, the contractual terms of which are described in greater detail above.

[2] 7 million SOs were granted in total during each of fiscal 2017 and 2016 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.