Revenues from External Customers and Long-Lived Assets, by Geographical Areas (Parenthetical) (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Feb. 28, 2013	May 31, 2012
Revenue from External Customer [Line Items]
Minimum percentage of revenue accounted for major customer	10.00%
Goodwill and other intangible assets	$ 4,187	$ 4,310

Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

No definition available.

Name:	us-gaap_IntangibleAssetsNetIncludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant