CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Loss, Net of Tax [Member]	Total
Beginning balance at Dec. 31, 2014	$ 34,591	$ 44,230	$ 116,169	$ (5,414)	$ (6,843)
Net income			14,050			$ 14,050
Dividend reinvestment	59	501
Stock options exercised	98	441
Stock-based compensation	142	484
Other comprehensive income					615	615
Cash dividends on common stock ($0.30 and $0.22 per share, respectively)			(2,583)
Ending balance at Sep. 30, 2015	34,890	45,656	127,636	(5,414)	(6,228)	196,540
Beginning balance at Jun. 30, 2015					(7,291)
Net income						4,923
Other comprehensive income						1,063
Ending balance at Sep. 30, 2015	34,890	45,656	127,636	(5,414)	(6,228)	196,540
Beginning balance at Dec. 31, 2015	34,916	46,239	130,093	(5,414)	(8,576)	197,258
Net income			16,098			16,098
Dividend reinvestment	166	1,619
Stock options exercised	0	0
Stock-based compensation	101	662
Other comprehensive income					2,353	2,353
Cash dividends on common stock ($0.30 and $0.22 per share, respectively)			(3,559)
Ending balance at Sep. 30, 2016	35,183	48,520	142,632	(5,414)	(6,223)	214,698
Beginning balance at Jun. 30, 2016					(5,499)
Net income						5,475
Other comprehensive income						(724)
Ending balance at Sep. 30, 2016	$ 35,183	$ 48,520	$ 142,632	$ (5,414)	$ (6,223)	$ 214,698