Certain Financial Statement Information (Details 11) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Mar. 31, 2012
Schedule of cost and estimated fair values of available-for-sale securities with stated maturities by contractual maturity
Less than 1 year, Cost	$ 16,038	$ 16,683
Mature in 1 - 2 years, Cost	24,201	26,869
Mature in 3 - 5 years, Cost	484	2,421
Mature after 5 years, Cost	1,237	1,467
Cost, Total	41,960	47,440
Less than 1 year, Fair Value	16,190	16,722
Mature in 1 - 2 years, Fair Value	24,284	27,026
Mature in 3 - 5 years, Fair Value	522	2,496
Mature after 5 years, Fair Value	1,447	1,537
Fair Value, Total	$ 42,443	$ 47,781

Available-for-sale securities, debt maturities, after five years, amortized cost.

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Available-for-sale securities, debt maturities, after five years, fair value.

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Available-for-sale securities, debt maturities, one to two years, amortized cost.

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Available-for-sale securities, debt maturities, three to five years, amortized cost.

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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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Amount of debt securities categorized neither as held-to-maturity nor trading.

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