Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2015	22,379
Balance at Dec. 31, 2015	$ 35,456	$ 19,340	$ 231,091	$ 632	$ 286,519
Net income			9,835		9,835
Other comprehensive income, net of tax				3,314	3,314
Stock compensation expense		513			513
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award (in shares)	105
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award	$ 349	1,029	(1,499)		(121)
Cash dividends			(3,737)		(3,737)
Shares cancelled (in shares)	(6)
Shares cancelled	$ (20)	(99)	119
Balance (in shares) at Mar. 31, 2016	22,478
Balance at Mar. 31, 2016	$ 35,785	20,783	235,809	3,946	296,323
Balance (in shares) at Dec. 31, 2016	22,617
Balance at Dec. 31, 2016	$ 36,250	26,682	252,439	(1,499)	313,872
Net income			10,791		10,791
Other comprehensive income, net of tax				774	774
Stock compensation expense		660			660
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award (in shares)	47
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award	$ 155	1,716	(3,976)		(2,105)
Cash dividends			(4,305)		(4,305)
Shares cancelled (in shares)	(3)
Shares cancelled	$ (10)	(56)	66
Balance (in shares) at Mar. 31, 2017	22,661
Balance at Mar. 31, 2017	$ 36,395	$ 29,002	$ 255,015	$ (725)	$ 319,687