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	27,728	0	0	27,728
Change in other comprehensive income (loss), net of tax	0	0	0	7,372	0	7,372
Cash dividend declared	0	0	(18,443)	0	0	(18,443)
Sale of treasury stock	0	(1,622)	0	0	3,798	2,176
Stock based compensation expense	0	268	0	0	0	268
Balance at Sep. 30, 2012	98,912	175,284	128,750	4,879	(50,208)	357,617
Balance at Dec. 31, 2012	98,912	174,899	132,378	1,558	(48,949)	358,798
Net Income	0	0	29,183	0	0	29,183
Change in other comprehensive income (loss), net of tax	0	0	0	(17,481)	0	(17,481)
Cash dividend declared	0	0	(18,546)	0	0	(18,546)
Sale of treasury stock	0	(1,737)	0	0	3,925	2,188
Stock based compensation expense	0	246	0	0	0	246
Balance at Sep. 30, 2013	$ 98,912	$ 173,408	$ 143,015	$ (15,923)	$ (45,024)	$ 354,388