Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total		Common Stock	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2016	$ 201,380		$ 8,578	$ 75,076	$ 119,600	$ (1,874)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,063				4,063
Other comprehensive income (loss)	489					489
Stock options exercised	73		3	70
Vesting of restricted stock			7	(7)
Equity based compensation	309		3	306
Cash dividends paid	(2,073)				(2,073)
Ending Balance at Mar. 31, 2017	204,241		8,591	75,445	121,590	(1,385)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification for ASU 2016-01 adoption	0				650	(650)
Beginning Balance at Dec. 31, 2017	208,717	[1]	8,604	76,179	127,010	(3,076)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,812				5,812
Other comprehensive income (loss)	(2,879)					(2,879)
Stock options exercised	85		3	82
Vesting of restricted stock			10	(10)
Equity based compensation	278		4	274
Cash dividends paid	(2,173)				(2,173)
Ending Balance at Mar. 31, 2018	$ 209,840		$ 8,621	$ 76,525	$ 131,299	$ (6,605)

[1] Derived from audited consolidated financial statements.