INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015	May 31, 2016
Income Tax Examination [Line Items]
Effective income tax rate	24.30%	17.60%	23.60%	20.80%
Net deferred tax assets	$ 183		$ 183		$ 1,100
Domestic Country [Member]
Income Tax Examination [Line Items]
Income tax examinations			Domestically, U.S. federal and state taxing authorities are currently examining income tax returns of Oracle and various acquired entities for years through fiscal 2015. Our U.S. federal income tax returns have been examined for all years prior to fiscal 2007, and we are no longer subject to audit for those periods. Our U.S. state income tax returns, with some exceptions, have been examined for all years prior to fiscal 2004, and we are no longer subject to audit for those periods.
Foreign Country [Member]
Income Tax Examination [Line Items]
Income tax examinations			Internationally, tax authorities for numerous non-U.S. jurisdictions are also examining returns affecting our unrecognized tax benefits. With some exceptions, we are generally no longer subject to tax examinations in non-U.S. jurisdictions for years prior to fiscal 1997.