Business Segments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jul. 31, 2012 Segment	Jul. 31, 2011	Jul. 31, 2010
Segment Reporting Information [Line Items]
Number of reportable segments	3
Net sales	$ 3,084,660	$ 2,755,508	$ 2,276,557
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Segment Reporting Information [Line Items]
Net sales	$ 463,130	$ 444,364	$ 364,105

Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 5

-Section 03

-Paragraph 1

Reference 2: 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(a))

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

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