EMPLOYEE BENEFIT PLANS Narrative (Details)	1 Months Ended		12 Months Ended
	Apr. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	May 31, 2021 Tranche shares	May 31, 2013 shares	May 31, 2020 shares	May 31, 2019 shares	May 31, 2018 shares
Stock-based Payment Award [Line Items]
Options outstanding			107,000,000		176,000,000	222,000,000	304,000,000
Options outstanding vested			67,000,000
Restricted stock-based awards outstanding			110,000,000		101,000,000	99,000,000	89,000,000
Stock options outstanding			31,000,000
Service-based stock options [Member]
Stock-based Payment Award [Line Items]
Expiration period			10 years
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 service period for market-based metric			3 years
2020 Plan [Member]
Stock-based Payment Award [Line Items]
Number of shares authorized			90,000,000
Shares of common stock available for future awards			210,000,000
2020 and 2000 Plan [Member]
Stock-based Payment Award [Line Items]
Vesting percentage			25.00%
Vesting period			4 years
Expiration period			10 years
2020 and 2000 Plan [Member] | Service-based stock options [Member]
Stock-based Payment Award [Line Items]
Options outstanding			69,000,000
Options outstanding vested			66,000,000
2020 and 2000 Plan [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding			107,000,000
Equivalent number of shares deducted against share pool (in actual number of shares)			2.5
2020 and 2000 Plan [Member] | Performance-based stock options [Member]
Stock-based Payment Award [Line Items]
Stock options outstanding			36,000,000
Acquired plans [Member]
Stock-based Payment Award [Line Items]
Options outstanding			1,000,000
Directors' Plan [Member]
Stock-based Payment Award [Line Items]
Vesting period			4 years
Expiration period			10 years
Options outstanding			1,000,000
Shares of common stock available for future awards			1,000,000
Increase in number of authorized shares of stock that may be issued				2,000,000
Directors' Plan [Member] | Restricted Stock Units [Member]
Stock-based Payment Award [Line Items]
Restricted stock-based awards outstanding			49,000
Maximum value of annual grants | $	$ 350,000	$ 400,000