Consolidated Statements of Changes in Stockholders’ Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance at Dec. 31, 2013	$ 9,581	$ 33,255	$ 188,825	$ (2,217)	$ 229,444
Balance (in Shares) at Dec. 31, 2013	14,609
Net income			26,100		26,100
Other comprehensive income (loss), net of tax				2,839	2,839
Stock compensation expense		1,459			1,459
Stock issued for exercise of stock options, net of withholdings to satisfy employee tax obligations upon vesting of stock awards	$ 269	1,870	(95)		2,044
Stock issued for exercise of stock options, net of withholdings to satisfy employee tax obligations upon vesting of stock awards (in Shares)	81
Stock issued for non-vested restricted stock	$ 132	1,022	(1,154)
Stock issued for non-vested restricted stock (in Shares)	40
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award	$ 18	(111)			(93)
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award (in Shares)	5
Cash dividends declared			(9,534)		(9,534)
Shares repurchased or cancelled	$ (102)	(784)	73		(813)
Shares repurchased or cancelled (in Shares)	(31)
Balance at Sep. 30, 2014	$ 9,898	36,711	204,215	622	251,446
Balance (in Shares) at Sep. 30, 2014	14,704
Balance at Dec. 31, 2014	$ 10,035	38,191	209,584	2,085	259,895
Balance (in Shares) at Dec. 31, 2014	14,745
Net income			27,541		27,541
Other comprehensive income (loss), net of tax				1,020	1,020
Stock compensation expense		1,561			1,561
Stock issued for exercise of stock options, net of withholdings to satisfy employee tax obligations upon vesting of stock awards	$ 307	2,383	(201)		2,489
Stock issued for exercise of stock options, net of withholdings to satisfy employee tax obligations upon vesting of stock awards (in Shares)	92
Stock issued for non-vested restricted stock	$ 116	1,088	(1,204)
Stock issued for non-vested restricted stock (in Shares)	35
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award	$ 60	(397)	(128)		(465)
Stock issued for share-based awards, net of withholdings to satisfy employee tax obligations upon award (in Shares)	18
Cash dividends declared			(10,519)		(10,519)
Shares repurchased or cancelled	$ (70)	(609)	105		(574)
Shares repurchased or cancelled (in Shares)	(21)
Balance at Sep. 30, 2015	$ 10,448	$ 42,217	$ 225,178	$ 3,105	$ 280,948
Balance (in Shares) at Sep. 30, 2015	14,869