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, 2015	$ 197,835		$ 8,605	$ 75,375	$ 111,565	$ 2,290
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,179				12,179
Other comprehensive income	468					468
Stock repurchased	(1,292)		(51)	(1,241)
Stock options exercised	101		4	97
Vesting of restricted stock			5	(5)
Equity based compensation	623		10	613
Cash dividends paid	(6,201)				(6,201)
Ending Balance at Sep. 30, 2016	203,713		8,573	74,839	117,543	2,758
Beginning Balance at Jun. 30, 2016						3,731
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,963
Other comprehensive income	(973)
Ending Balance at Sep. 30, 2016	203,713		8,573	74,839	117,543	2,758
Beginning Balance at Dec. 31, 2016	201,380	[1]	8,578	75,076	119,600	(1,874)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	13,129				13,129
Other comprehensive income	1,038					1,038
Stock options exercised	114		5	109
Vesting of restricted stock			7	(7)
Equity based compensation	775		10	765
Cash dividends paid	(6,222)				(6,222)
Ending Balance at Sep. 30, 2017	210,214		8,600	75,943	126,507	(836)
Beginning Balance at Jun. 30, 2017						(1,028)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,787
Other comprehensive income	192
Ending Balance at Sep. 30, 2017	$ 210,214		$ 8,600	$ 75,943	$ 126,507	$ (836)

[1] Derived from audited consolidated financial statements.