General - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Stock-based compensation	$ 62	$ 57
Lease liability and related right-of-use asset	13,000
Operating income	$ 1,117	1,264
Stock Repurchase Program Number Of Shares Authorized To Be Repurchased	25,000,000
Number of Shares Repurchased	400,000
Treasury Stock Acquired, Average Cost Per Share	$ 207.92
Payments for Repurchase of Common Stock	$ 86	222
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	15,600,000
Dividends Payable, Date Declared	Aug. 18, 2017
Dividends Payable Amount Per Share	$ 0.50
Dividends Payable, Date To Be Paid	Oct. 02, 2017
Dividends Payable, Date Of Record	Sep. 11, 2017
ASU 201703 [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Operating income	$ 146	$ 112