Income Taxes - Schedule of Reconciliation of Total Income Tax Expense and Amount Computed by Statutory Federal Income Tax Rate to Income Before Taxes (Parenthetical) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Feb. 28, 2018	May 31, 2019	May 31, 2018	May 31, 2017
Income Taxes [Line Items]
Provisional benefit related to remeasurement of net U.S. deferred tax liability	$ (1,150)		$ (1,150)
Foreign deferred tax benefits		$ (17)	(579)	$ (108)
U.S. deferred tax expenses		$ (61)	271	989
Corporate Structuring Transactions [Member]
Income Taxes [Line Items]
Foreign deferred tax benefits			434	94
U.S. deferred tax expenses			179	$ 26
U.S. Plans [Member]
Income Taxes [Line Items]
Additional provisional amount recognized one time benefit	$ 204		$ 204