Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Employee Stock Ownership Plan [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Gain (Loss) [Member]	Treasury Stock [Member]	Common Stock Acquired by Deferred Compensation Plan [Member]	Deferred Compensation Plan Liability [Member]
Beginning Balance at Dec. 31, 2013	$ 214,350	$ (3,616)	$ 336	$ 263,319	$ 206,201	$ (6,619)	$ (245,271)	$ (665)	$ 665
Net income	9,824				9,824
Other comprehensive income, net of tax	(283)					(283)
Tax benefit of stock plans	50			50
Stock awards	429			429
Treasury stock allocated to restricted stock plan				661	(97)		(564)
Purchased 301,766 and 259,940 shares of common stock in 2014 and 2015 respectively	(5,020)						(5,020)
Allocation of ESOP stock	291	158		133
Cash dividend $0.24 and $0.26 per share for 2014 and 2015 respectively	(4,065)				(4,065)
Exercise of stock options	265				(44)		309
Sale/Purchase of stock for the deferred compensation plan								350	(350)
Ending Balance at Jun. 30, 2014	215,841	(3,458)	336	264,592	211,819	(6,902)	(250,546)	(315)	315
Beginning Balance at Dec. 31, 2014	218,259	(3,330)	336	265,260	217,714	(7,109)	(254,612)	(304)	304
Net income	10,395				10,395
Other comprehensive income, net of tax	522					522
Tax benefit of stock plans	8			8
Stock awards	638			638
Treasury stock allocated to restricted stock plan				1,197	(139)		(1,058)
Purchased 301,766 and 259,940 shares of common stock in 2014 and 2015 respectively	(4,452)						(4,452)
Allocation of ESOP stock	288	143		145
Cash dividend $0.24 and $0.26 per share for 2014 and 2015 respectively	(4,288)				(4,288)
Exercise of stock options	165				(38)		203
Sale/Purchase of stock for the deferred compensation plan								(5)	5
Ending Balance at Jun. 30, 2015	$ 221,535	$ (3,187)	$ 336	$ 267,248	$ 223,644	$ (6,587)	$ (259,919)	$ (309)	$ 309