Balance Sheet Accounts (Schedule of Available-for-sale Investments by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Amortized Cost
Due in 1 year or less	$ 40,701
Due in 1-2 years	35,353
Due in 2-5 years	29,477
Due in more than 5 years	0
Total investments in available for sale debt securities	105,531
Fair Value
Due in 1 year or less	40,828
Due in 1-2 years	35,443
Due in 2-5 years	29,621
Due in more than 5 years	0
Total investments in available for sale debt securities	$ 105,892

Available-for-sale Securities, Debt Maturities, After Year Five, Amortized Cost Basis

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Available-for-sale Securities, Debt Maturities, After Year Five, Fair Value

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Available-for-sale Securities, Debt Maturities, After Year One and Before Two, Amortized Cost Basis

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Available-for-sale Securities, Debt Maturities, After Year Two Through Five, Amortized Cost Basis

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Amount of available-for-sale debt securities at cost, net of adjustments, which 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 cost, net of adjustments, maturing in the next 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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