Components of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands		12 Months Ended
		May 31, 2017	May 31, 2016	May 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance		$ 919,846	$ 840,049	$ 944,882
Income taxes		542	(12,141)	8,866
Balance		1,073,929	919,846	840,049
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance		(18,728)	(20,717)
Other comprehensive income (loss) before reclassifications		1,370	1,989
Balance		(17,358)	(18,728)	(20,717)
Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance		(17,061)	(15,003)
Other comprehensive income (loss) before reclassifications		2,841	(3,667)
Reclassification adjustments to income	[1]	559	434
Income taxes		(1,158)	1,175
Balance		(14,819)	(17,061)	(15,003)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance		7,224	(14,984)
Other comprehensive income (loss) before reclassifications		7,669	7,283
Reclassification adjustments to income	[1]	(12,191)	28,241
Income taxes		1,700	(13,316)
Balance		4,402	7,224	(14,984)
Accumulated Other Comprehensive Loss, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance		(28,565)	(50,704)	(3,581)
Other comprehensive income (loss) before reclassifications		11,880	5,605
Reclassification adjustments to income	[1]	(11,632)	28,675
Income taxes		542	(12,141)
Balance		$ (27,775)	$ (28,565)	$ (50,704)

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