Other Comprehensive Income (Loss) Components and Related Taxes on Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011
Components Of Other Comprehensive Income Loss [Line Items]
Unrealized holding gains arising during the period	$ 213	$ 1,288
Other-Than-Temporary Impaired included in income
Reclassifications of net gains included in income		(12)
Other comprehensive income before tax	213	1,276
Deferred tax expense	59	354
Other comprehensive income	$ 154	$ 922

Before tax amount of the income statement impact of the reclassification adjustment for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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+ Details

- Definition

Before tax and reclassification adjustments amount of unrealized holding gain (loss) and transfers on available-for-sale securities.

+ References

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-Name Accounting Research Bulletin (ARB)

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+ Details