CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2013	$ 321,875	$ 93,249	$ 233,108	$ (2,494)	$ (1,988)
Balance (in shares) at Dec. 31, 2013		16,377,449
Comprehensive income:
Net income	21,224		21,224
Other comprehensive income (loss), net of tax	5,846			5,846
Cash dividends declared	(6,617)		(6,617)
Treasury shares purchased under deferred directors' plan (in shares)		(6,022)
Treasury shares purchased under deferred directors' plan	0	$ 230			(230)
Treasury stock sold and distributed under deferred directors' plan (in shares)		25,031
Treasury stock sold and distributed under deferred directors' plan		$ (432)			432
Stock activity under equity compensation plans (in shares)		62,901
Stock activity under equity compensation plans	(70)	$ (70)
Stock based compensation expense	1,228	1,228
Balance at Jun. 30, 2014	343,486	$ 94,205	247,715	3,352	(1,786)
Balance (in shares) at Jun. 30, 2014		16,459,359
Balance at Dec. 31, 2014	361,296	$ 96,121	263,345	3,830	(2,000)
Balance (in shares) at Dec. 31, 2014		16,465,621
Comprehensive income:
Net income	22,516		22,516
Other comprehensive income (loss), net of tax	(1,108)			(1,108)
Cash dividends declared	(7,560)		(7,560)
Treasury shares purchased under deferred directors' plan (in shares)		(5,288)
Treasury shares purchased under deferred directors' plan	0	$ 213			(213)
Stock activity under equity compensation plans (in shares)		67,864
Stock activity under equity compensation plans	(390)	$ (390)
Stock based compensation expense	921	921
Balance at Jun. 30, 2015	$ 375,675	$ 96,865	$ 278,301	$ 2,722	$ (2,213)
Balance (in shares) at Jun. 30, 2015		16,528,197