Balance Sheet Accounts (Schedule of Available-for-sale Investments by Contractual Maturity) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013
Amortized Cost
Due in 1 year or less	$ 42,255
Due in 1-2 years	39,499
Due in 2-5 years	29,611
Total investments in available for sale debt securities	111,365
Fair Value
Due in 1 year or less	42,336
Due in 1-2 years	39,652
Due in 2-5 years	29,519
Total investments in available for sale debt securities	$ 111,507

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

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