Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

Property, Plant and Equipment - Additional Information (Detail) (USD $)				6 Months Ended
	Nov. 30, 2013	May 31, 2013	Nov. 30, 2013 Alvin Texas	Nov. 30, 2013 Capitalized ERP System Development Costs	Nov. 30, 2013 Capitalized ERP System Development Costs Minimum	Nov. 30, 2013 Capitalized ERP System Development Costs Maximum
Property, Plant and Equipment [Line Items]
Expected total future capital costs associated with the implementation					$ 10,000,000	$ 12,000,000
project implenentation period				2 years
Construction in progress, costs	193,177,000	179,990,000	3,500,000	850,000
Estimated cost of project			$ 9,000,000