Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate	24.70%	23.60%
Federal statutory rate	35.00%	35.00%
Favorable discrete tax adjustments for excess tax benefits related to equity compensation	$ 1,500,000	$ 10,400,000
Discrete tax expense (benefit)	(9,000,000)
Discrete tax charge related to intercompany distribution	7,300,000
Discrete tax benefit related to change in estimated deferred income tax liability	16,300,000
Unremitted foreign earnings	290,400,000
Deferred income tax liability	85,400,000
Reduction to deferred tax liability offset by increase due to foreign currency translation	7,600,000
Provision for deferred income taxes	$ 0