Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Balance, shares at Dec. 31, 2016	20,969,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation, shares	67,000
Balance, shares at Dec. 31, 2017	21,036,000
Balance at Dec. 31, 2016	$ 210,214	$ 210	$ 153,353	$ 53,640	$ 3,011
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of stock under stock-based compensation plan	1,077	0	1,077
Stock-based compensation expense	652		652
Dividends declared	(5,039)			(5,039)
Other comprehensive income (loss), net of income tax	6,384				6,384
Net income	24,901			24,901
Balance at Dec. 31, 2017	238,189	210	155,082	73,502	9,395
Balance (Accounting Standards Update 2016-01 [Member]) at Dec. 31, 2017				79,992	2,905
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment - unrealized gains on equity securities, net of tax | Accounting Standards Update 2016-01 [Member]	$ 0			6,490	(6,490)
Stock-based compensation, shares	206,000
Balance, shares at Dec. 31, 2018	21,241,504
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Reclassification of tax effect of TCJA | Accounting Standards Update 2018-02 [Member]	$ 0			(1,308)	1,308
Issuance of stock under stock-based compensation plan	1,808	2	1,806
Stock-based compensation expense	1,597		1,597
Dividends declared	(5,926)			(5,926)
Other comprehensive income (loss), net of income tax	(5,469)				(5,469)
Net income	33,787			33,787
Balance at Dec. 31, 2018	$ 263,986	212	158,485	106,545	(1,256)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued, shares	742,000
Stock-based compensation, shares	229,000
Restricted shares withheld for taxes, shares	(7,000)
Balance, shares at Dec. 31, 2019	22,205,665
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issuance, net of transaction costs	$ 65,879	8	65,871
Issuance of stock under stock-based compensation plan	2,750	2	2,748
Stock-based compensation expense	2,742		2,742
Restricted shares withheld for taxes	(617)		(617)
Dividends declared	(6,950)			(6,950)
Other comprehensive income (loss), net of income tax	14,774				14,774
Net income	63,316			63,316
Balance at Dec. 31, 2019	$ 405,880	$ 222	$ 229,229	$ 162,911	$ 13,518