Summary of Tax Years Open to Examination by Major Tax Jurisdiction (Detail)	12 Months Ended
	May. 31, 2015
UNITED STATES | Federal
Income Tax Examination [Line Items]
Tax years open to examination by major jurisdiction
UNITED STATES | State and Local Jurisdiction
Income Tax Examination [Line Items]
Tax years open to examination by major jurisdiction
AUSTRIA
Income Tax Examination [Line Items]
Tax years open to examination by major jurisdiction
CANADA
Income Tax Examination [Line Items]
Tax years open to examination by major jurisdiction
Mexico
Income Tax Examination [Line Items]
Tax years open to examination by major jurisdiction