Amounts in Accumulated Other Comprehensive Income (Loss) that have not yet been Recognized in Net Periodic Pension Cost, but will be Recognized in Consolidated Statements of Income (Detail) $ in Thousands	12 Months Ended
	May. 31, 2015 USD ($)
Pension Benefits, U.S. Plans
Schedule of Pension Amounts in Accumulated Other Comprehensive Income (Loss) [Line Items]
Net actuarial loss	$ (15,624)
Prior service (costs)	(234)
Pension Benefits, Non-U.S. Plans
Schedule of Pension Amounts in Accumulated Other Comprehensive Income (Loss) [Line Items]
Net actuarial loss	(1,825)
Prior service (costs)	$ (39)