SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Investment in Short-Term Securities (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Investment in Short-Term Securities
Investment in short-term securities	$ 9,163	$ 15,837
US Treasury Securities
Investment in Short-Term Securities
Investment in short-term securities	5,998	12,499
Debt Securities
Investment in Short-Term Securities
Investment in short-term securities	0	2,143
Certificates of Deposit
Investment in Short-Term Securities
Investment in short-term securities	$ 3,165	$ 1,195

Investments which are intended to be sold in the short term (usually less than one year or the normal operating cycle, whichever is longer) including trading securities, available-for-sale securities, held-to-maturity securities, and other short-term investments not otherwise listed in the existing taxonomy.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 1

-Subparagraph g

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 210.5-02.2)

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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