Income Taxes (Income Before Provision for Income Taxes) (Details) (USD $)	12 Months Ended
Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Income Taxes [Abstract]
US	$ 102,159,000	$ 97,217,000	$ 72,384,000
Foreign	(355,000)	85,000	885,000
Income before provision for income taxes	$ 101,804,000	$ 97,302,000	$ 73,269,000

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph h
-Subparagraph 1(i)

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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