Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Current
Federal	$ 50,200	$ 42,837	$ 57,511
State and local	2,954	2,157	2,731
Foreign	7,593	6,639	5,490
Current Income Tax Expense (Benefit), Total	60,747	51,633	65,732
Deferred
Federal	18,177	7,584	(37,839)
State and local	476	934	(754)
Foreign	(210)	(1,164)	(1,367)
Provision for (benefit from) deferred income taxes	18,443	7,354	(39,960)
Income tax expense	$ 79,190	$ 58,987	$ 25,772