Consolidated Statements Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance (in shares) at Dec. 31, 2017	24,668,390
Balance at Dec. 31, 2017	$ 2,467	$ 127,122	$ 224,315	$ 546	$ 354,450
Net income			11,111		11,111
Other comprehensive income (loss)				(8,186)	(8,186)
Reclassification of stranded tax effects upon the adoption of ASU 2018-02			277	(277)
Shares withheld upon the vesting and conversion of RSUs (in shares)	(25,321)
Shares withheld upon the vesting and conversion of RSUs	$ (3)	(719)			(722)
Common stock issued under stock compensation plans (in shares)	112,237
Common stock issued under stock compensation plans	$ 11	101			112
Common stock issued under dividend reinvestment and stock purchase plan (in shares)	269,361
Common stock issued under dividend reinvestment and stock purchase plan	$ 27	7,292			7,319
Stock-based compensation		1,128			1,128
Cash dividends declared			(3,766)		(3,766)
Balance (in shares) at Mar. 31, 2018	25,024,667
Balance at Mar. 31, 2018	$ 2,502	134,924	231,937	(7,917)	361,446
Balance (in shares) at Dec. 31, 2018	25,422,740
Balance at Dec. 31, 2018	$ 2,542	145,163	249,922	(9,440)	388,187
Net income			10,841		10,841
Other comprehensive income (loss)				4,862	4,862
Repurchase of common stock (in shares)	(674,800)
Repurchase of common stock	$ (67)	(15,264)			(15,331)
Shares withheld upon the vesting and conversion of RSUs (in shares)	(39,947)
Shares withheld upon the vesting and conversion of RSUs	$ (4)	(826)			(830)
Common stock issued under stock compensation plans (in shares)	122,456
Common stock issued under stock compensation plans	$ 12	223			235
Common stock issued under dividend reinvestment and stock purchase plan (in shares)	69,898
Common stock issued under dividend reinvestment and stock purchase plan	$ 7	1,427			1,434
Stock-based compensation		1,295			1,295
Cash dividends declared			(4,251)		(4,251)
Balance (in shares) at Mar. 31, 2019	24,900,347
Balance at Mar. 31, 2019	$ 2,490	$ 132,018	$ 256,512	$ (4,578)	$ 386,442