Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2015	$ 201,913	$ 77,827	$ 123,301	$ (1,114)	$ 1,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,540		20,540
Reclassification of certain tax effects from accumulated other comprehensive income to retained earnings					0
Other comprehensive income (loss)	(2,020)				(2,020)
Restricted stock award grants	0	(896)		896
Stock-based compensation expense	820	820
Purchase of treasury stock	(44)			(44)
Reissue of treasury stock	121	(14)		135
Cash dividends declared	(9,546)		(9,546)
Ending balance at Dec. 31, 2016	211,784	77,737	134,295	(127)	(121)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23,860		23,860
Reclassification of certain tax effects from accumulated other comprehensive income to retained earnings	0		237		(237)
Other comprehensive income (loss)	15				15
Forfeiture of restricted stock award grants	0	67		(67)
Restricted stock award grants	0	(984)		984
Stock-based compensation expense	928	928
Issuance of common stock, net of issuance costs	19,294	19,294
Purchase of treasury stock	(1,877)			(1,877)
Cash dividends declared	(10,094)		(10,094)
Ending balance at Dec. 31, 2017	243,910	97,042	148,298	(1,087)	(343)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	33,719		33,719
Reclassification of certain tax effects from accumulated other comprehensive income to retained earnings					0
Other comprehensive income (loss)	(3,653)				(3,653)
Forfeiture of restricted stock award grants	0	11		(11)
Restricted stock award grants	0	(996)		996
Stock-based compensation expense	1,545	1,545
Purchase of treasury stock	(2,454)			(2,454)
Cash dividends declared	(10,237)		(10,237)
Ending balance at Dec. 31, 2018	$ 262,830	$ 97,602	$ 171,780	$ (2,556)	$ (3,996)