Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Aug. 31, 2013	May 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,505	$ 2,505
Accumulated Amortization	(1,509)	(1,468)
Customer relationships, Net Carrying Amount	585
Net Carrying Amount	996	1,037
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Customer Relationships, Gross Carrying Amount	2,094	2,094
Accumulated Amortization	(1,509)	(1,468)
Customer relationships, Net Carrying Amount	585	626
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	3 years	3 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Life	8 years	8 years
Trade name
Finite-Lived Intangible Assets [Line Items]
Trade names, Gross Carrying Amount	411	411
Trade names, Net Carrying Amount	$ 411	$ 411