Components of Changes in Other Comprehensive Income (Loss) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014		Feb. 28, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance			$ (12,036)
Other comprehensive income before reclassifications			5,130
Reclassification adjustments to income			6,826	[1]
Income taxes	(273)	128	(2,050)		(911)
Accumulated other comprehensive loss, ending balance	(2,130)		(2,130)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance			4,025
Other comprehensive income before reclassifications			5,846
Accumulated other comprehensive loss, ending balance	9,871		9,871
Pension Liability Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance			(10,221)
Other comprehensive income before reclassifications			691
Income taxes			(241)
Accumulated other comprehensive loss, ending balance	(9,771)		(9,771)
Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss, beginning balance			(5,840)
Other comprehensive income before reclassifications			(1,407)
Reclassification adjustments to income			6,826	[1]
Income taxes			(1,809)
Accumulated other comprehensive loss, ending balance	$ (2,230)		$ (2,230)

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