Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (USD $) In Thousands	Capital Stock [Member]	Surplus [Member]	Undivided Profits [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2011	$ 98,912	$ 176,638	$ 119,465	$ (2,493)	$ (54,006)	$ 338,516
Net Income	0	0	17,975	0	0	17,975
Change in other comprehensive income (loss), net of tax	0	0	0	4,078	0	4,078
Cash dividend declared	0	0	(12,287)	0	0	(12,287)
Sale of treasury stock	0	(1,044)	0	0	2,490	1,446
Stock based compensation expense	0	179	0	0	0	179
Balance at Jun. 30, 2012	98,912	175,773	125,153	1,585	(51,516)	349,907
Balance at Dec. 31, 2012	98,912	174,899	132,378	1,558	(48,949)	358,798
Net Income	0	0	18,931	0	0	18,931
Change in other comprehensive income (loss), net of tax	0	0	0	(18,389)	0	(18,389)
Cash dividend declared	0	0	(12,356)	0	0	(12,356)
Sale of treasury stock	0	(1,173)	0	0	2,641	1,468
Stock based compensation expense	0	171	0	0	0	171
Balance at Jun. 30, 2013	$ 98,912	$ 173,897	$ 138,953	$ (16,831)	$ (46,308)	$ 348,623