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
Balances at Dec. 31, 2016	$ 127	$ 64,201	$ 90,964	$ (993)	$ 154,299
Net income			8,564		8,564
Other comprehensive income (loss)				939	939
Stock-based compensation		748			748
Cash dividends declared			(1,902)		(1,902)
Balances at Sep. 30, 2017	127	64,949	97,626	(54)	162,648
Balances at Dec. 31, 2017	127	65,256	99,662	(1,309)	163,736
Net income			12,903		12,903
Other comprehensive income (loss)				(2,763)	(2,763)
Stock-based compensation		474			474
Cash dividends declared			(2,931)		(2,931)
Balances at Sep. 30, 2018	$ 127	$ 65,730	109,628	(4,066)	$ 171,419
Cumulative effect adjustment			$ (6)	$ 6