CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at Dec. 31, 2017	$ 239	$ 304,932	$ 18,753	$ (1,152)	$ 322,772
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			17,126		17,126
Changes in other comprehensive income on investment securities, net of tax and accreation				(2,138)	(2,138)
Dividends on common stock			(3,839)		(3,839)
Issuance of common stock under Stock Incentive Plan	1	359			360
Stock-based compensation expense		169			169
Reclassification from accumulated other comprehensive loss to retained earnings due to adoption of ASU 2018-02			229	(229)
Balance at Jun. 30, 2018	240	305,460	32,269	(3,519)	334,450
Balance at Mar. 31, 2018	240	305,360	25,324	(2,859)	328,065
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			8,867		8,867
Changes in other comprehensive income on investment securities, net of tax and accreation				(660)	(660)
Dividends on common stock			(1,922)		(1,922)
Issuance of common stock under Stock Incentive Plan		6			6
Stock-based compensation expense		94			94
Balance at Jun. 30, 2018	240	305,460	32,269	(3,519)	334,450
Balance at Dec. 31, 2018	240	305,654	44,985	(2,589)	348,290
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			15,339		15,339
Changes in other comprehensive income on investment securities, net of tax and accreation				3,108	3,108
Dividends on common stock			(4,341)		(4,341)
Issuance of common stock under Stock Incentive Plan	1	128			129
Stock-based compensation expense		267			267
Balance at Jun. 30, 2019	241	306,049	55,983	519	362,792
Balance at Mar. 31, 2019	241	305,879	48,300	(1,731)	352,689
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			9,319		9,319
Changes in other comprehensive income on investment securities, net of tax and accreation				2,250	2,250
Dividends on common stock			(2,171)		(2,171)
Issuance of common stock under Stock Incentive Plan		7			7
Stock-based compensation expense		163			163
Balance at Jun. 30, 2019	$ 241	$ 306,049	55,983	$ 519	362,792
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Impact of adoption of ASU 2016-02			$ 535		$ 535