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, 2015	14,116,677
Balance at Dec. 31, 2015	$ 1,412	$ 56,931	$ 185,069	$ 7,524	$ 250,936
Net income			15,364		15,364
Other comprehensive income				6,168	6,168
Common stock issued in public offering, net of issuance costs (in shares)	1,300,000
Common stock issued in public offering, net of issuance costs	$ 130	35,132			35,262
Shares withheld upon the vesting and conversion of RSUs (in shares)	(13,393)
Shares withheld upon the vesting and conversion of RSU	$ (1)	(369)			(370)
Common stock issued under stock compensation plans (in shares)	82,762
Common stock issued under stock compensation plans	$ 8	462			470
Common stock issued under dividend reinvestment and stock purchase plan (in shares)	104,648
Common stock issued under dividend reinvestment and stock purchase plan	$ 10	2,889			2,899
Stock-based compensation		914			914
Cash dividends declared			(5,991)		(5,991)
Balance (in shares) at Jun. 30, 2016	15,590,694
Balance at Jun. 30, 2016	$ 1,559	95,959	194,442	13,692	305,652
Balance (in shares) at Dec. 31, 2016	23,699,107
Balance at Dec. 31, 2016	$ 2,370	101,738	203,326	(1,604)	305,830
Net income			18,214		18,214
Other comprehensive income				3,110	3,110
Shares withheld upon the vesting and conversion of RSUs (in shares)	(19,339)
Shares withheld upon the vesting and conversion of RSU	$ (2)	(525)			(527)
Common stock issued under stock compensation plans (in shares)	126,878
Common stock issued under stock compensation plans	$ 13	618			631
Common stock issued under dividend reinvestment and stock purchase plan (in shares)	322,620
Common stock issued under dividend reinvestment and stock purchase plan	$ 32	8,407			8,439
Stock-based compensation		1,331			1,331
Cash dividends declared			(6,753)		(6,753)
Balance (in shares) at Jun. 30, 2017	24,129,266
Balance at Jun. 30, 2017	$ 2,413	$ 111,569	$ 214,787	$ 1,506	$ 330,275