Consolidated Statement of Shareholders' Equity (USD $)	Total	Preferred Stock	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at beginning of period at Dec. 31, 2009	$ 243,968,000	$ 38,543,000	$ 166,227,000	$ 46,229,000	$ 9,487,000	$ (16,518,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,581,000			5,581,000
Other comprehensive loss, net of tax	(13,940,000)				(13,940,000)
Stock Issued During Period, Value, Stock Options Exercised	427,000		(428,000)			855,000
Dividends, Preferred Stock	(1,950,000)			(1,950,000)
Amortization of discount on preferred stock	0	102,000		(102,000)
Common stock cash dividends declared	(4,211,000)			4,211,000
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	4,000		4,000
Reissuance of treasury stock for deferred compensation plan	488,000					488,000
Purchase of treasury stock	(181,000)					(181,000)
Common shares issued under dividend reinvestment plan	403,000		403,000
Stock based compensation expense	92,000		92,000
Balance at end of period at Dec. 31, 2010	230,681,000	38,645,000	166,298,000	45,547,000	(4,453,000)	(15,356,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,555,000			12,555,000
Other comprehensive loss, net of tax	5,865,000				5,865,000
Dividends, Preferred Stock	(988,000)			(988,000)
Amortization of discount on preferred stock	0	355,000		(355,000)
Common stock cash dividends declared	(3,179,000)			(3,179,000)
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	1,000		1,000
Reissuance of treasury stock for deferred compensation plan	176,000					176,000
Purchase of treasury stock	(187,000)					(187,000)
Common shares issued under dividend reinvestment plan	318,000		318,000
Common shares issued under Board of Directors' compensation plan	105,000		42,000			63,000
Stock based compensation expense	310,000		310,000
Repurchase of preferred shares and common stock warrant		(39,000,000)
Balance at end of period at Dec. 31, 2011	206,657,000	0	166,969,000	53,580,000	1,412,000	(15,304,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,385,000			20,385,000
Other comprehensive loss, net of tax	(758,000)				(758,000)
Repurchase of common stock warrant	(1,201,000)		(1,201,000)
Common stock cash dividends declared	(4,807,000)			(4,807,000)
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	16,000		16,000
Reissuance of treasury stock for deferred compensation plan	163,000					163,000
Purchase of treasury stock	(156,000)					(156,000)
Common shares issued under dividend reinvestment plan	357,000		357,000
Common shares issued under Board of Directors' compensation plan	130,000		(44,000)			174,000
Stock based compensation expense	942,000		942,000
Repurchase of preferred shares and common stock warrant	(39,000,000)
Balance at end of period at Dec. 31, 2012	$ 221,728,000	$ 0	$ 167,039,000	$ 69,158,000	$ 654,000	$ (15,123,000)