Summary of Significant Accounting Policies Sales Incentives (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Accounting Policies [Abstract]
Sales Discounts, Goods	$ 20,209	$ 18,474	$ 18,826

Aggregate cash discounts given by the entity for goods sold to customers including, but not limited to, early payments of accounts due. For example, selling terms of "2/10, net 30" entitle a customer to a 2% discount for prompt payment within 10 days, otherwise full payment is expected in 30 days. Discounts are a deduction from gross revenue in arriving at net revenue.

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(a))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

Name:	us-gaap_SalesDiscountsGoods
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration