EMPLOYEE BENEFIT PLANS Narrative (Details)	1 Months Ended		12 Months Ended
	Apr. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	May 31, 2020 Tranche shares		May 31, 2019 shares	May 31, 2018 shares		May 31, 2014 shares	May 31, 2013 shares	May 31, 2011 shares	May 31, 2017 shares
Stock-based Payment Award [Line Items]
Options outstanding			176,000,000		222,000,000	304,000,000					312,000,000
Options outstanding vested			113,000,000
Restricted stock-based awards outstanding			101,000,000		99,000,000	89,000,000					83,000,000
Stock options outstanding			49,000,000
Restricted stock-based awards granted (in shares)			50,000,000		53,000,000	44,000,000
Restricted stock-based awards vested (in shares)			34,000,000		31,000,000	27,000,000
Stock options granted			0	[1]	7,000,000	77,000,000	[2]
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, maximum			5 years
Award service period for market-based metric			3 years
Service-based stock options [Member]
Stock-based Payment Award [Line Items]
Expiration period			10 years
Performance-based restricted stock awards [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding			300,000
Restricted stock-based awards granted (in shares)			0		0	0
Restricted stock-based awards vested (in shares)			1,100,000
Executive Officers [Member]
Stock-based Payment Award [Line Items]
Stock options granted						66,500,000
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			120,000,000
Options outstanding vested			112,000,000
Shares of common stock available for future awards			212,000,000
2000 Plan [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding			97,000,000
Equivalent number of shares deducted against share pool (in actual number of shares)			2.5
2000 Plan [Member] | Employee Stock Options [Member]
Stock-based Payment Award [Line Items]
Stock options outstanding			54,000,000
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
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			81,000
Non-employee Director [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Maximum value of annual grants | $	$ 350,000	$ 400,000
Acquired plans [Member]
Stock-based Payment Award [Line Items]
Options outstanding			1,000,000

[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