Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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-Name Accounting Research Bulletin (ARB)

-Number 43

-Section A

-Paragraph 4, 5

-Chapter 3

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-Name Accounting Standards Codification

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-Name Statement of Financial Accounting Standard (FAS)

-Number 133

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+ Details

- Definition

Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

+ References

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-Name Accounting Standards Codification

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+ Details

Fair Value of Financial Instruments Fair Value of Financial Instruments (Details 4) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2013	Jul. 31, 2012	Apr. 30, 2013 Level 1	Jul. 31, 2012 Level 1	Apr. 30, 2013 Level 2	Jul. 31, 2012 Level 2	Apr. 30, 2013 Level 3	Jul. 31, 2012 Level 3	Apr. 30, 2013 U.S. agency securities	Apr. 30, 2013 U.S. agency securities Level 1	Apr. 30, 2013 U.S. agency securities Level 2	Apr. 30, 2013 U.S. agency securities Level 3	Apr. 30, 2013 Commercial paper	Apr. 30, 2013 Commercial paper Level 1	Apr. 30, 2013 Commercial paper Level 2	Apr. 30, 2013 Commercial paper Level 3	Apr. 30, 2013 Corporate Bond Securities [Member]	Apr. 30, 2013 Corporate Bond Securities [Member] Level 1	Apr. 30, 2013 Corporate Bond Securities [Member] Level 2	Apr. 30, 2013 Corporate Bond Securities [Member] Level 3	Apr. 30, 2013 Foreign Government Debt Securities [Member]	Apr. 30, 2013 Foreign Government Debt Securities [Member] Level 1	Apr. 30, 2013 Foreign Government Debt Securities [Member] Level 2	Apr. 30, 2013 Foreign Government Debt Securities [Member] Level 3	Apr. 30, 2013 Municipal debt securities	Jan. 31, 2013 Municipal debt securities	Apr. 30, 2013 Municipal debt securities Level 1	Jan. 31, 2013 Municipal debt securities Level 1	Apr. 30, 2013 Municipal debt securities Level 2	Jan. 31, 2013 Municipal debt securities Level 2	Apr. 30, 2013 Municipal debt securities Level 3	Jan. 31, 2013 Municipal debt securities Level 3	Apr. 30, 2013 U.S. agency securities	Apr. 30, 2013 U.S. agency securities Level 1	Apr. 30, 2013 U.S. agency securities Level 2	Apr. 30, 2013 U.S. agency securities Level 3	Apr. 30, 2013 Commercial paper	Apr. 30, 2013 Commercial paper Level 1	Apr. 30, 2013 Commercial paper Level 2	Apr. 30, 2013 Commercial paper Level 3	Apr. 30, 2013 Money Market Funds [Member]	Jul. 31, 2012 Money Market Funds [Member]	Apr. 30, 2013 Money Market Funds [Member] Level 1	Jul. 31, 2012 Money Market Funds [Member] Level 1	Apr. 30, 2013 Money Market Funds [Member] Level 2	Jul. 31, 2012 Money Market Funds [Member] Level 2	Apr. 30, 2013 Money Market Funds [Member] Level 3	Jul. 31, 2012 Money Market Funds [Member] Level 3	Jul. 31, 2012 Certificates of deposit	Jul. 31, 2012 Certificates of deposit Level 1	Jul. 31, 2012 Certificates of deposit Level 2	Jul. 31, 2012 Certificates of deposit Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 186,038	$ 108,833	$ 42,021	$ 108,833	$ 144,017	$ 0	$ 0	$ 0																									$ 1,683	$ 0	$ 1,683	$ 0	$ 29,271	$ 0	$ 29,271	$ 0	$ 42,021	$ 105,107	$ 42,021	$ 105,107	$ 0	$ 0	$ 0	$ 0	$ 3,726	$ 3,726	$ 0	$ 0
Available-for-sale Securities, Current									6,466	0	6,466	0	28,775	0	28,775	0	26,378	0	26,378	0	787	0	787	0		1,185		0		1,185		0
Available-for-sale Securities, Noncurrent									$ 22,992	$ 0	$ 22,992	$ 0					$ 21,470	$ 0	$ 21,470	$ 0					$ 5,010		$ 0		$ 5,010		$ 0