Comprehensive Income (Loss) - Components of Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		May 31, 2018	May 31, 2018	May 31, 2017	May 31, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			$ 1,073,929	$ 919,846	$ 840,049
Other comprehensive income before reclassifications			28,753	11,880
Reclassification adjustments to income	[1]		(13,156)	(11,632)
Reclassification of stranded tax effects		$ 1,701	(1,701)
Income taxes			(701)	542	(12,141)
Balance		1,036,375	1,036,375	1,073,929	919,846
Foreign Currency Translation
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(17,358)	(18,728)
Other comprehensive income before reclassifications			12,371	1,370
Balance		(4,987)	(4,987)	(17,358)	(18,728)
Pension Liability Adjustment
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(14,819)	(17,061)
Other comprehensive income before reclassifications			1,402	2,841
Reclassification adjustments to income	[1]		473	559
Reclassification of stranded tax effects			(2,818)
Income taxes			(309)	(1,158)
Balance		(16,071)	(16,071)	(14,819)	(17,061)
Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			4,402	7,224
Other comprehensive income before reclassifications			14,980	7,669
Reclassification adjustments to income	[1]		(13,629)	(12,191)
Reclassification of stranded tax effects			1,117
Income taxes			(392)	1,700
Balance		6,478	6,478	4,402	7,224
Accumulated Other Comprehensive Loss, Net of Tax
Accumulated Other Comprehensive Income Loss [Line Items]
Balance			(27,775)	(28,565)	(50,704)
Reclassification of stranded tax effects			(1,701)
Balance		$ (14,580)	$ (14,580)	$ (27,775)	$ (28,565)

[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.