Marketable Securities (Details 1) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013
Legal maturities of debt investments
Amortized Cost, Less than one year	$ 99,964
Amortized Cost, Due in 1-2 years	14,996
Amortized Cost, Total	114,960
Estimated Fair Value, Less than one year	99,981
Estimated Fair Value, Due in 1-2 years	15,022
Estimated Fair Value	$ 115,003

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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Amount of available-for-sale debt securities at fair value maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year.

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