Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	CAPITAL IN EXCESS OF STATED VALUE	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	RETAINED EARNINGS (DEFICIT)	Class A Common Stock	Class A Common Stock COMMON STOCK	Class B Common Stock	Class B Common Stock COMMON STOCK
Beginning Balance (in shares) at May. 31, 2017						329		1,314
Beginning balance at May. 31, 2017	$ 12,407	$ 5,710	$ (213)	$ 6,907		$ 0		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised (in shares)								24
Stock options exercised	600	600
Repurchase of Class B Common Stock (in shares)								(70)
Repurchase of Class B Common Stock	(4,267)	(254)		(4,013)
Dividends on common stock and preferred stock	(1,265)			(1,265)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								4
Issuance of shares to employees, net of shares withheld for employee taxes	82	110		(28)
Stock-based compensation	218	218
Net income	1,933			1,933
Other comprehensive income (loss)	104		104
Ending Balance (in shares) at May. 31, 2018						329		1,272
Ending balance at May. 31, 2018	9,812	6,384	(92)	3,517		$ 0		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised (in shares)								18
Stock options exercised	539	539
Conversion to Class B Common Stock (in shares)						(14)		14
Conversion to Class B Common Stock	0
Repurchase of Class B Common Stock (in shares)								(54)
Repurchase of Class B Common Stock	(4,283)	(227)		(4,056)
Dividends on common stock and preferred stock	(1,360)			(1,360)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								3
Issuance of shares to employees, net of shares withheld for employee taxes	139	142		(3)
Stock-based compensation	325	325
Net income	4,029			4,029
Other comprehensive income (loss)	323		323
Ending Balance (in shares) at May. 31, 2019					315	315	1,253	1,253
Ending balance at May. 31, 2019	9,040	7,163	231	1,643		$ 0		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised (in shares)								20
Stock options exercised	703	703
Repurchase of Class B Common Stock (in shares)								(34)
Repurchase of Class B Common Stock	(3,033)	(161)		(2,872)
Dividends on common stock and preferred stock	(1,491)			(1,491)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								4
Issuance of shares to employees, net of shares withheld for employee taxes	156	165		(9)
Stock-based compensation	429	429
Net income	2,539			2,539
Other comprehensive income (loss)	(287)		(287)
Ending Balance (in shares) at May. 31, 2020					315	315	1,243	1,243
Ending balance at May. 31, 2020	$ 8,055	$ 8,299	$ (56)	$ (191)		$ 0		$ 3