Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1,2)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Name:	us-gaap_GrossProfit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Quarterly Information - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	May 31, 2012	Feb. 29, 2012	Nov. 30, 2011	Aug. 31, 2011	May 31, 2013	May 31, 2012
Schedule Of Quarterly Financial Information [Line Items]
Gross Profit	$ 24,684	$ 22,160	$ 24,388	$ 22,022	$ 24,125	$ 20,883	$ 22,588	$ 21,740	$ 93,254	$ 89,336
Revision Adjustment
Schedule Of Quarterly Financial Information [Line Items]
Gross Profit					$ (2,478)	$ (2,680)	$ (2,780)	$ (2,773)