Summary of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Nov. 30, 2014	May 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 36,583	$ 36,211
Accumulated Amortization	(14,367)	(12,698)
Net Carrying Amount	22,216us-gaap_FiniteLivedIntangibleAssetsNet	23,513us-gaap_FiniteLivedIntangibleAssetsNet
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	22,901	22,424
Accumulated Amortization	(7,969)	(6,739)
Net Carrying Amount	14,932	15,685
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,562	3,667
Accumulated Amortization	(3,421)	(3,430)
Net Carrying Amount	141	237
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,325	4,325
Accumulated Amortization	(867)	(717)
Net Carrying Amount	3,458	3,608
Technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,112	5,112
Accumulated Amortization	(1,964)	(1,698)
Net Carrying Amount	3,148	3,414
Licenses
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	683	683
Accumulated Amortization	(146)	(114)
Net Carrying Amount	$ 537	$ 569

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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