Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Dec. 31, 2016		$ 21,382	$ 228,142	$ 170,377	$ (78,833)	$ (2,011)	$ 339,057
Net income				21,485			21,485
Reclassification of certain tax effects				244		(244)
Other comprehensive income (loss)						1,415	1,415
Common dividends declared				(11,563)			(11,563)
Equity-based compensation expense			382		408		790
Common stock options exercised			86		292		378
Issuance of treasury stock to 401(k) plan			140		275		415
Purchase of treasury shares					(1,263)		(1,263)
Balance at Dec. 31, 2017		21,382	228,750	180,543	(79,121)	(840)	350,714
Net income				36,340			36,340
Other comprehensive income (loss)						(589)	(589)
Common dividends declared				(12,966)			(12,966)
Equity-based compensation expense			535		623		1,158
Common stock options exercised			(84)		468		384
Issuance of treasury stock to 401(k) plan			138		214		352
Purchase of treasury shares					(34,412)		(34,412)
Special common dividend declared				(8,124)			(8,124)
Reclassification of treasury stock		(5,375)	(106,853)		112,228
Balance at Dec. 31, 2018		16,007	122,486	195,793		(1,429)	332,857
Net income				38,802			38,802
Other comprehensive income (loss)						(77)	(77)
Common dividends declared				(15,060)			(15,060)
Equity-based compensation expense		44	1,437				1,481
Common stock options exercised		8	128				136
Issuance of treasury stock to 401(k) plan		12	399				411
Purchase of treasury shares		(487)	(15,875)				(16,362)
Highlands Bankshares, Inc. acquisition		2,793	83,838				86,631
Balance at Dec. 31, 2019		$ 18,377	$ 192,413	$ 219,535		$ (1,506)	$ 428,819