Income Taxes (Detail) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	May 31, 2020
Income Tax Contingency [Line Items]
Federal income tax rate	11.50%	12.40%
Total gross unrecognized tax benefits, excluding related interest and penalties	$ 860		$ 771
Total gross unrecognized tax benefits, excluding related interest and penalties, amount which would affect the Company's effective tax rate if recognized in future periods	584
Income tax expense	197	$ 194
Increase (decrease) in liability for payment of interest and penalties	(21)
Accrued interest and penalties related to uncertain tax positions (excluding federal benefit)	179		$ 158
Estimated decrease in total gross unrecognized tax benefits as a result of resolutions of global tax examinations and expiration of applicable statutes of limitations	50
Altera Corp. V. Commissioner
Income Tax Contingency [Line Items]
Unrecognized tax benefits recognized	77
Income tax expense	$ 71