CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2012	$ 295,652	$ 1,024	$ 91,453	$ 213,674	$ (10,499)
Common Stock, Shares Outstanding, Beginning Balance at Dec. 31, 2012		16,380,000
Net income	7,421			7,421
Total other comprehensive income (loss), net of tax	1,181				1,181
Cash dividends declared	(4,175)			(4,175)
Share-based compensation	581		581
Deferred compensation plan, shares		2,000
Deferred compensation plan	30	0	30
Exercise of stock options, issuance of other compensation-related equity instruments and related tax benefit, shares		43,000
Exercise of stock options, issuance of other compensation-related equity instruments and related tax benefit	601	3	598
Stockholders' Equity, Ending Balance at Mar. 31, 2013	301,291	1,027	92,662	216,920	(9,318)
Common Stock, Shares Outstanding, Ending Balance at Mar. 31, 2013		16,425,000
Stockholders' Equity, Beginning Balance at Dec. 31, 2013	329,646	1,038	97,566	232,595	(1,553)
Common Stock, Shares Outstanding, Beginning Balance at Dec. 31, 2013	16,379,771	16,614,000
Net income	9,298			9,298
Total other comprehensive income (loss), net of tax	776				776
Cash dividends declared	(4,894)			(4,894)
Share-based compensation	491		491
Exercise of stock options, issuance of other compensation-related equity instruments and related tax benefit, shares		21,000
Exercise of stock options, issuance of other compensation-related equity instruments and related tax benefit	541	2	539
Stockholders' Equity, Ending Balance at Mar. 31, 2014	$ 335,858	$ 1,040	$ 98,596	$ 236,999	$ (777)
Common Stock, Shares Outstanding, Ending Balance at Mar. 31, 2014	16,634,985	16,635,000