Consolidated Statements Of Changes In Shareholders' Equity (USD $) In Thousands	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Deferred Compensation Arrangements [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2008	$ 67	$ 36,862	$ 57,302	$ (19,853)	$ 6,117	$ (1,185)	$ 79,310
Net income	0	0	12,479	0	0	0	12,479
Dividends paid	0	0	(6,829)	0	0	0	(6,829)
Sale of treasury stock	0	(1)	0	5	0	0	4
Distribution of stock under deferred compensation arrangements	0	0	0	400	(400)	0	0
Shares issued under stock plans, net of excess tax benefit	0	(496)	0	1,080	178	0	762
Share based compensation expense	0	65	0	0	0	0	65
Dividend reinvestment plan	0	(152)	0	570	351	0	769
Cumulative effect adjustment upon adoption of ASC 320-10-65, net of tax	0	0	213	0	0	(213)	0
Other comprehensive income/ loss	0	0	0	0	0	4,065	4,065
Balance at Dec. 31, 2009	67	36,278	63,165	(17,798)	6,246	2,667	90,625
Net income	0	0	15,461	0	0	0	15,461
Dividends paid	0	0	(6,901)	0	0	0	(6,901)
Sale of treasury stock	0	0	0	10	0	0	10
Distribution of stock under deferred compensation arrangements	0	0	0	455	(455)	0	0
Shares issued under stock plans, net of excess tax benefit	0	(7)	0	63	207	0	263
Share based compensation expense	0	101	0	0	0	0	101
Dividend reinvestment plan	0	(24)	0	434	352	0	762
Other comprehensive income/ loss	0	0	0	0	0	(990)	(990)
Balance at Dec. 31, 2010	67	36,348	71,725	(16,836)	6,350	1,677	99,331
Net income	0	0	14,620	0	0	0	14,620
Dividends paid	0	0	(6,952)	0	0	0	(6,952)
Purchase of treasury stock	0	1	0	13	0	0	14
Distribution of stock under deferred compensation arrangements	0	0	0	432	(432)	0	0
Shares issued under stock plans, net of excess tax benefit	0	19	0	273	(76)	0	216
Share based compensation expense	0	110	0	0	54	0	164
Dividend reinvestment plan	0	66	0	301	352	0	719
Other comprehensive income/ loss	0	0	0	0	0	1,425	1,425
Balance at Dec. 31, 2011	$ 67	$ 36,544	$ 79,393	$ (15,817)	$ 6,248	$ 3,102	$ 109,537