Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 767	$ 842	$ 1,717	$ 2,091
Other comprehensive income (loss), net of tax:
Change in net foreign currency translation adjustment	(8)	(14)	14	(11)
Change in net gains (losses) on cash flow hedges	8	323	(387)	83
Change in net gains (losses) on other	(1)	5	(1)	9
Total other comprehensive income (loss), net of tax	(1)	314	(374)	81
TOTAL COMPREHENSIVE INCOME	$ 766	$ 1,156	$ 1,343	$ 2,172