Components of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands		3 Months Ended
		Aug. 31, 2017	Aug. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2017		$ 1,073,929
Income taxes		(1,112)	$ (463)
Balance as of August 31, 2017		1,082,727
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2017		(17,358)
Other comprehensive income before reclassifications		15,433
Balance as of August 31, 2017		(1,925)
Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2017		(14,819)
Income taxes		(6)
Balance as of August 31, 2017		(14,825)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2017		4,402
Other comprehensive income before reclassifications		6,798
Reclassification adjustments to income	[1]	(3,805)
Income taxes		(1,106)
Balance as of August 31, 2017		6,289
Accumulated Other Comprehensive Loss, Net of Tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of May 31, 2017		(27,775)
Other comprehensive income before reclassifications		22,231
Reclassification adjustments to income	[1]	(3,805)
Income taxes		(1,112)
Balance as of August 31, 2017		$ (10,461)

[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."