Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	May 31, 2019	May 31, 2018	May 31, 2017	May 31, 2016
Income Tax Contingency [Line Items]
Federal income tax rate	21.00%	29.20%	35.00%
Tax Cuts And Jobs Act Of 2017, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense		$ 1,875
Tax Cuts And Jobs Act Of 2017, incomplete accounting, deferred tax asset, provisional income tax expense		$ 158
Income tax benefits attributable to employee stock-based compensation			$ 177
Effective tax rate, change from prior period		(5.50%)
Total gross unrecognized tax benefits, excluding related interest and penalties	$ 808	$ 698	461	$ 506
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	582
Increase (decrease) in liability for payment of interest and penalties	(17)	(14)	38
Accrued interest and penalties related to uncertain tax positions (excluding federal benefit)	174	157
Estimated decrease in total gross unrecognized tax benefits as a result of resolutions of global tax examinations and expiration of applicable statutes of limitations	$ 210
Tax holiday, expiration period	2021
Decrease in income tax expense related to tax holiday	$ 167	$ 126	$ 187
Decrease in income tax expense related to tax holiday per diluted share, (in dollars per share)	$ 0.10	$ 0.08	$ 0.11
Valuation allowance increase (decrease) related to tax benefits of certain subsidiaries with operating losses	$ 7	$ 13	$ 30
Available domestic and foreign loss carry-forwards	257
Deferred income taxes and other liabilities
Income Tax Contingency [Line Items]
Long-term income taxes payable	$ 902	$ 993