Components of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				$ 919,846
Income taxes		$ (395)	$ 1,282	(858)	$ 674
Balance as of November 30, 2016		1,010,762		1,010,762
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				(18,728)
Other comprehensive income (loss) before reclassifications				(8,039)
Balance as of November 30, 2016		(26,767)		(26,767)
Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				(17,061)
Balance as of November 30, 2016		(17,061)		(17,061)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				7,224
Other comprehensive income (loss) before reclassifications				8,050
Reclassification adjustments to income	[1]			(4,915)
Income taxes				(858)
Balance as of November 30, 2016		9,501		9,501
Accumulated Other Comprehensive Loss, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				(28,565)
Balance as of November 30, 2016		(34,327)		(34,327)
Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2016				793,371
Other comprehensive income (loss) before reclassifications				11
Reclassification adjustments to income	[1]			(4,915)
Income taxes				(858)
Balance as of November 30, 2016		$ 884,940		$ 884,940

[1] The statement of earnings classification of amounts reclassified to income for cash flow hedges is disclosed in "NOTE N - Derivative Instruments and Hedging Activities."