Securities (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	$ 298,384,000			$ 298,384,000		$ 301,979,000
Gross Unrealized Gains	11,269,000			11,269,000		8,440,000
Gross Unrealized Losses	(1,279,000)			(1,279,000)		(2,177,000)
Fair Value	308,374,000			308,374,000		308,242,000
Amortized Cost [Abstract]
Due in one year or less	4,863,000			4,863,000
Due after one year through five years	22,698,000			22,698,000
Due after five years through ten years	31,943,000			31,943,000
Due after ten years	32,432,000			32,432,000
Total	298,384,000			298,384,000
Fair Value [Abstract]
Due in one year or less	4,892,000			4,892,000
Due after one year through five years	22,772,000			22,772,000
Due after five years through ten years	33,717,000			33,717,000
Due after ten years	33,923,000			33,923,000
Total	308,374,000			308,374,000
Sale proceeds of securities				39,500,000
Gains on sale of securities	164,000		141,000	452,000	263,000
Tax expense related to realized gains				154,000
Carrying value of securities pledged for fiduciary powers	143,200,000			143,200,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(347,000)			(347,000)		(919,000)
Twelve Months or Greater	(932,000)			(932,000)		(1,258,000)
Total	(1,279,000)			(1,279,000)		(2,177,000)
Fair Value [Abstract]
Less than Twelve Months	27,074,000			27,074,000		47,976,000
Twelve Months or Greater	8,625,000			8,625,000		10,595,000
Total	35,699,000			35,699,000		58,571,000
Amount of OTTI Related to Credit Loss		142,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Number of securities temporarily impaired	51			51
Number of securities temporarily impaired in investment grade	50			50
Number of securities temporarily impaired in speculative grade	1			1
Amount of OTTI Related to Credit Loss		142,000
Net impairment recognized in earnings through end of period						2,400,000
Credit related impairment losses on securities				0	22,000
U.S. government agencies [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	13,246,000			13,246,000		9,068,000
Gross Unrealized Gains	411,000			411,000		293,000
Gross Unrealized Losses	(3,000)			(3,000)		(18,000)
Fair Value	13,654,000			13,654,000		9,343,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(3,000)			(3,000)		(18,000)
Twelve Months or Greater	0			0		0
Total	(3,000)			(3,000)		(18,000)
Fair Value [Abstract]
Less than Twelve Months	2,568,000			2,568,000		2,045,000
Twelve Months or Greater	57,000			57,000		26,000
Total	2,625,000			2,625,000		2,071,000
Obligations of states and political subdivisions [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	70,460,000			70,460,000		65,090,000
Gross Unrealized Gains	3,852,000			3,852,000		2,503,000
Gross Unrealized Losses	(8,000)			(8,000)		(51,000)
Fair Value	74,304,000			74,304,000		67,542,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(8,000)			(8,000)		0
Twelve Months or Greater	0			0		(51,000)
Total	(8,000)			(8,000)		(51,000)
Fair Value [Abstract]
Less than Twelve Months	1,302,000			1,302,000		43,000
Twelve Months or Greater	0			0		2,243,000
Total	1,302,000			1,302,000		2,286,000
Mortgage-backed Securities, Agency [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	159,790,000			159,790,000		181,797,000
Gross Unrealized Gains	5,994,000			5,994,000		5,482,000
Gross Unrealized Losses	(272,000)			(272,000)		(209,000)
Fair Value	165,512,000			165,512,000		187,070,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(272,000)			(272,000)		(209,000)
Twelve Months or Greater	0			0		0
Total	(272,000)			(272,000)		(209,000)
Fair Value [Abstract]
Less than Twelve Months	16,213,000			16,213,000		22,768,000
Twelve Months or Greater	0			0		0
Total	16,213,000			16,213,000		22,768,000
Mortgage-backed Securities, Non-agency [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	15,015,000			15,015,000		18,737,000
Gross Unrealized Gains	298,000			298,000		67,000
Gross Unrealized Losses	(8,000)			(8,000)		(598,000)
Fair Value	15,305,000			15,305,000		18,206,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(8,000)			(8,000)		(103,000)
Twelve Months or Greater	0			0		(495,000)
Total	(8,000)			(8,000)		(598,000)
Fair Value [Abstract]
Less than Twelve Months	2,760,000			2,760,000		4,773,000
Twelve Months or Greater	0			0		4,522,000
Total	2,760,000			2,760,000		9,295,000
Other Asset-backed Securities [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	31,575,000			31,575,000		16,110,000
Gross Unrealized Gains	703,000			703,000		90,000
Gross Unrealized Losses	(86,000)			(86,000)		(404,000)
Fair Value	32,192,000			32,192,000		15,796,000
Amortized Cost [Abstract]
Total	31,575,000			31,575,000
Fair Value [Abstract]
Total	32,192,000			32,192,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	(56,000)			(56,000)		(362,000)
Twelve Months or Greater	(30,000)			(30,000)		(42,000)
Total	(86,000)			(86,000)		(404,000)
Fair Value [Abstract]
Less than Twelve Months	4,231,000			4,231,000		10,572,000
Twelve Months or Greater	1,431,000			1,431,000		1,467,000
Total	5,662,000			5,662,000		12,039,000
Corporate Preferred Stock [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	68,000			68,000		68,000
Gross Unrealized Gains	0			0		0
Gross Unrealized Losses	(7,000)			(7,000)		(28,000)
Fair Value	61,000			61,000		40,000
Amortized Cost [Abstract]
Total	68,000			68,000
Fair Value [Abstract]
Total	61,000			61,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	0			0		0
Twelve Months or Greater	(7,000)			(7,000)		(28,000)
Total	(7,000)			(7,000)		(28,000)
Fair Value [Abstract]
Less than Twelve Months	0			0		0
Twelve Months or Greater	32,000			32,000		11,000
Total	32,000			32,000		11,000
Corporate securities [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost	8,230,000			8,230,000		10,612,000
Gross Unrealized Gains	11,000			11,000		5,000
Gross Unrealized Losses	(895,000)			(895,000)		(641,000)
Fair Value	7,346,000			7,346,000		9,976,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months	0			0		(227,000)
Twelve Months or Greater	(895,000)			(895,000)		(414,000)
Total	(895,000)			(895,000)		(641,000)
Fair Value [Abstract]
Less than Twelve Months	0			0		7,775,000
Twelve Months or Greater	7,105,000			7,105,000		2,057,000
Total	7,105,000			7,105,000		9,832,000
Trust-preferred securities [Member]
Amortized costs and fair values of securities available for sale [Abstract]
Amortized Cost						497,000
Gross Unrealized Gains						0
Gross Unrealized Losses						(228,000)
Fair Value						269,000
Gross Unrealized Losses [Abstract]
Less than Twelve Months						0
Twelve Months or Greater						(228,000)
Total						(228,000)
Fair Value [Abstract]
Less than Twelve Months						0
Twelve Months or Greater						269,000
Total						269,000
Amount of OTTI Related to Credit Loss	149,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Amount of OTTI Related to Credit Loss	149,000
Mortgage-backed securities [Member]
Amortized Cost [Abstract]
Total	174,805,000			174,805,000
Fair Value [Abstract]
Total	$ 180,817,000			$ 180,817,000