Consolidated Statements of Changes In Shareholders' Equity - USD ($) shares in Thousands, $ 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, 2012	$ 67	$ 36,742	$ 87,580	$ (14,786)	$ 6,403	$ 2,215	$ 118,221
Net income			15,131				15,131
Dividends paid ($1.12 per share)			(7,054)				(7,054)
Sale of treasury stock		3		12			15
Shares granted under stock plans and deferral of director fees, including excess tax benefit		223		140	61		424
Share based compensation (benefit) expense		27			160		187
Dividend reinvestment plan		134		141	347		622
Other comprehensive income (loss)						(7,935)	(7,935)
Balance at Dec. 31, 2013	67	37,129	95,657	(14,043)	6,521	(5,720)	119,611
Distribution of stock under deferred compensation arrangements				450	(450)
Net income			12,125				12,125
Dividends paid ($1.12 per share)			(7,085)				(7,085)
Sale of treasury stock				(82)			(82)
Purchase of treasury stock							(82)
Shares granted under stock plans and deferral of director fees, including excess tax benefit		275		164	22		461
Share based compensation (benefit) expense				(122)	241		119
Dividend reinvestment plan				(335)	335
Other comprehensive income (loss)						672	672
Balance at Dec. 31, 2014	$ 67	37,404	100,697	(13,865)	6,566	(5,048)	125,821
Distribution of stock under deferred compensation arrangements				553	(553)
Net income			12,618				12,618
Dividends paid ($1.12 per share)			(7,096)				(7,096)
Purchase accounting		17,428					17,433
Purchase accounting (in shares)	5
Purchase of treasury stock				(41)			(41)
Shares granted under stock plans and deferral of director fees, including excess tax benefit		231		(81)	108		258
Share based compensation (benefit) expense					36		36
Dividend reinvestment plan				(325)	325
Other comprehensive income (loss)						(975)	(975)
Balance at Dec. 31, 2015	$ 72	$ 55,063	$ 106,219	(13,798)	6,521	$ (6,023)	$ 148,054
Distribution of stock under deferred compensation arrangements				$ 514	$ (514)