Amortized Cost and Fair Value of Investments by Contractual Maturity (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Amortized cost
Debt securities due within one year	$ 9,473
Debt securities due within one to five years	29,476
Debt securities due within five years or more	3,278
Total	42,227
Fair value
Debt securities due within one year	9,496
Debt securities due within one to five years	29,726
Debt securities due within five years or more	3,360
Total	$ 42,582

Available for sale Securities, Debt Maturities, after Five Years, Amortized Cost

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This item represents the fair value of debt securities which are expected to mature after five years from the balance sheet date which are categorized neither as held-to-maturity nor trading securities.

+ References

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Available For Sale Securities Debt Maturities Fair Value Total

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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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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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