Summary of Other Intangible Assets by Class (Detail) (USD $) In Thousands, unless otherwise specified	May 31, 2014	May 31, 2013
Other Intangible Assets [Line Items]
Indefinite-lived intangible assets, cost	$ 8,481	$ 27,581
Cost	181,499	173,813
Definite-lived intangible assets, cost	173,018	146,232
Accumulated Amortization	35,506	26,669
Trademarks
Other Intangible Assets [Line Items]
Indefinite-lived intangible assets, cost	8,481	27,581
Patents and Trademarks
Other Intangible Assets [Line Items]
Definite-lived intangible assets, cost	4,696	15,111
Accumulated Amortization	148	2,201
Customer Relationships
Other Intangible Assets [Line Items]
Definite-lived intangible assets, cost	143,585	113,098
Accumulated Amortization	28,257	18,967
Non-compete Agreements
Other Intangible Assets [Line Items]
Definite-lived intangible assets, cost	10,733	11,669
Accumulated Amortization	4,263	3,427
Other Intangible Assets
Other Intangible Assets [Line Items]
Definite-lived intangible assets, cost	14,004	6,354
Accumulated Amortization	$ 2,838	$ 2,074