Unaudited Condensed 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	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, 2018						329		1,272
Beginning 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)								8
Stock options exercised	260	260
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)								(34)
Repurchase of Class B Common Stock	(2,632)	(137)		(2,495)
Dividends on common stock and preferred stock	(666)			(666)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								2
Issuance of shares to employees, net of shares withheld for employee taxes	66	67		(1)
Stock-based compensation	133	133
Net income	1,939			1,939
Other comprehensive income (loss)	301		301
Ending Balance (in shares) at Nov. 30, 2018						315		1,262
Ending balance at Nov. 30, 2018	8,729	6,707	209	1,810		$ 0		$ 3
Beginning Balance (in shares) at Aug. 31, 2018						320		1,269
Beginning balance at Aug. 31, 2018	8,992	6,525	(30)	2,494		$ 0		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised (in shares)								2
Stock options exercised	78	78
Conversion to Class B Common Stock (in shares)						(5)		5
Conversion to Class B Common Stock	0
Repurchase of Class B Common Stock (in shares)								(16)
Repurchase of Class B Common Stock	(1,251)	(68)		(1,183)
Dividends on common stock and preferred stock	(348)			(348)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								2
Issuance of shares to employees, net of shares withheld for employee taxes	80	80
Stock-based compensation	92	92
Net income	847			847
Other comprehensive income (loss)	239		239
Ending Balance (in shares) at Nov. 30, 2018						315		1,262
Ending balance at Nov. 30, 2018	8,729	6,707	209	1,810		$ 0		$ 3
Beginning Balance (in shares) at May. 31, 2019					315	315	1,253	1,253
Beginning 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)								11
Stock options exercised	381	381
Repurchase of Class B Common Stock (in shares)								(22)
Repurchase of Class B Common Stock	(1,917)	(102)		(1,815)
Dividends on common stock and preferred stock	(727)			(727)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								2
Issuance of shares to employees, net of shares withheld for employee taxes	82	87		(5)
Stock-based compensation	190	190
Net income	2,482			2,482
Other comprehensive income (loss)	(179)		(179)
Ending Balance (in shares) at Nov. 30, 2019					315	315	1,244	1,244
Ending balance at Nov. 30, 2019	9,351	7,719	52	1,577		$ 0		$ 3
Beginning Balance (in shares) at Aug. 31, 2019						315		1,245
Beginning balance at Aug. 31, 2019	9,200	7,296	180	1,721		$ 0		$ 3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock options exercised (in shares)								7
Stock options exercised	265	265
Repurchase of Class B Common Stock (in shares)								(10)
Repurchase of Class B Common Stock	(922)	(47)		(875)
Dividends on common stock and preferred stock	(383)			(383)
Issuance of shares to employees, net of shares withheld for employee taxes (in shares)								2
Issuance of shares to employees, net of shares withheld for employee taxes	94	95		(1)
Stock-based compensation	110	110
Net income	1,115			1,115
Other comprehensive income (loss)	(128)		(128)
Ending Balance (in shares) at Nov. 30, 2019					315	315	1,244	1,244
Ending balance at Nov. 30, 2019	$ 9,351	$ 7,719	$ 52	$ 1,577		$ 0		$ 3