Earning Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic Earnings Per Share
Net income	$ 7,246	$ 3,484	$ 6,552
Dividends and accretion on preferred stock	(1,446)	(2,115)	(1,803)
Income available to common stockholders	5,800	1,369	4,749
Diluted Earnings Per Share
Income available to common stockholders and assumed conversions	$ 5,800	$ 1,369	$ 4,749
Weighted-Average Shares number of common shares, basic	6,951,727	6,907,015	6,873,508
Weighted-Average Shares, effect of dilutive securities stock option	103,957	69,619	22,599
Weighted-Average Shares income available to common stockholders and assumed conversions, diluted	7,055,684	6,976,634	6,896,107
Earnings per share, basic	$ 0.83	$ 0.20	$ 0.69
Earnings per share, diluted	$ 0.82	$ 0.20	$ 0.69

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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