Short-term Investments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Schedule Of Available For Sale Securities [Line Items]
Short-term Investments, Amortized Cost	$ 19,965	$ 19,900
Short-term Investments, Unrealized Losses	(7)	(39)
Short-term Investments, Estimated Fair Value	19,958us-gaap_AvailableForSaleSecurities	19,861us-gaap_AvailableForSaleSecurities
Corporate
Schedule Of Available For Sale Securities [Line Items]
Short-term Investments, Amortized Cost	15,122	14,262
Short-term Investments, Unrealized Losses	(5)	(27)
Short-term Investments, Estimated Fair Value	15,117	14,235
Government
Schedule Of Available For Sale Securities [Line Items]
Short-term Investments, Amortized Cost	4,843	5,638
Short-term Investments, Unrealized Losses	(2)	(12)
Short-term Investments, Estimated Fair Value	$ 4,841	$ 5,626

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

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-Publisher FASB

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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

-Publisher FASB

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This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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