Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands	Series A Preferred Stock [Member] Retained Earnings [Member]	Series A Preferred Stock [Member]	Series B Preferred Stock [Member] Retained Earnings [Member]	Series B Preferred Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Balance at Dec. 31, 2010					$ 9,700	$ 110,056	$ 4,941	$ 21,633	$ (17,698)	$ (7,675)	$ 120,957
Net income								10,304			10,304
Other comprehensive income, net of tax										3,110	3,110
Accretion of discount on preferred stock					62			(62)
Redemption of series A preferred stock					(10,000)						(10,000)
Proceeds from stock offerings					11,250						11,250
Issuance cost of common stock								(4)			(4)
Cash dividend on preferred stock	(354)	(354)	(23)	(23)
Cash dividends declared on common stock								(1,466)			(1,466)
Stock issued for options exercise									7		7
Stock-based compensation expense							27				27
Balance at Sep. 30, 2011					11,012	110,056	4,968	30,028	(17,691)	(4,565)	133,808
Balance at Dec. 31, 2011					11,250	110,056	4,715	32,695	(17,354)	(5,446)	135,916
Net income								13,038			13,038
Other comprehensive income, net of tax										10,619	10,619
Issuance cost of common stock								(6)			(6)
Cash dividend on preferred stock			(253)	(253)
Cash dividends declared on common stock								(2,288)			(2,288)
Stock issued for options exercise							12		120		132
Stock-based compensation expense							27				27
Balance at Sep. 30, 2012					$ 11,250	$ 110,056	$ 4,754	$ 43,186	$ (17,234)	$ 5,173	$ 157,185