Common Stock and Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Millions	9 Months Ended
	Feb. 28, 2017 USD ($) $ / shares shares	Feb. 29, 2016 $ / shares
Class A Convertible Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, no par value (in dollars per share) | $ / shares	$ 0
Common stock, shares authorized (in shares) | shares	400,000,000
Common stock, conversion basis	Each share of Class A Common Stock is convertible into one share of Class B Common Stock.
Common stock, Class A conversion ratio to Class B (in shares)	1
Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, no par value (in dollars per share) | $ / shares	$ 0
Common stock, shares authorized (in shares) | shares	2,400,000,000
Shares available for grant (in shares) | shares	718,000,000
Employee Stock Option | Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vesting period	4 years
Stock options expiration from the date of grant	10 years
Unrecognized compensation costs from stock options, net of estimated forfeitures | $	$ 236
Unrecognized compensation costs from stock options, net of estimated forfeitures, to be recognized as operating overhead expense over a weighted average period	2 years 2 months 12 days
Weighted average fair value per share of the options granted (in dollars per share) | $ / shares	$ 9.38	$ 12.67
Minimum term of market traded options for estimates of expected volatility	1 year
ESPPs | Class B Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plans, payroll deductions	10.00%
Employee stock purchase plan offering period	6 months