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, 2014	$ 173,780	$ 7,872	$ 57,650	$ 104,594		$ 3,664
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,039			15,039
Other comprehensive loss	(1,374)					(1,374)
Issuance of common stock	20,483	826	19,657
Stock repurchased	(3,506)	(151)	(3,355)
Stock options exercised	789	43	746
Equity-based compensation	692	15	677
Cash dividends paid	(8,068)			(8,068)
Ending Balance at Dec. 31, 2015	197,835	8,605	75,375	111,565		2,290
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,301			16,301
Other comprehensive loss	(4,164)					(4,164)
Stock repurchased	(1,292)	(51)	(1,241)
Stock options exercised	142	6	136
Vesting of restricted stock		5	(5)
Equity-based compensation	824	13	811
Cash dividends paid	(8,266)			(8,266)
Ending Balance at Dec. 31, 2016	201,380	8,578	75,076	119,600		(1,874)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,249			15,249
Other comprehensive loss	(657)					(657)
Reclass stranded tax effects from tax rate change	(545)			545	[1]	(545)	[1]
Stock options exercised	113	5	108
Vesting of restricted stock		8	(8)
Equity-based compensation	1,016	13	1,003
Cash dividends paid	(8,384)			(8,384)
Ending Balance at Dec. 31, 2017	$ 208,717	$ 8,604	$ 76,179	$ 127,010		$ (3,076)

[1] See Note 1 for Adoption of New Accounting Standards