CONDENSED CONSOLIDATED BALANCE SHEETS PARENTHETICAL - USD ($) $ in Millions	Aug. 31, 2019	May 31, 2019
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 383	$ 371
Preferred stock par value per share	$ 0.01	$ 0.01
Preferred stock shares authorized	1,000,000.0	1,000,000.0
Preferred stock shares outstanding	0	0
Common stock par value per share	$ 0.01	$ 0.01
Common stock shares authorized	11,000,000,000	11,000,000,000
Common stock shares outstanding	3,296,000,000	3,359,000,000