Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income
Balance at Dec. 31, 2012	$ 205,075	$ 7,273	$ 17,731	$ 174,650	$ 5,421
Balance (in shares) at Dec. 31, 2012		13,915
Increase (Decrease) in Stockholders' Equity
Net income	6,768			6,768
Other comprehensive income (loss), net of tax	(478)				(478)
Stock compensation expense	531		531
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards	79	10	69
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards (in shares)		3
Stock issued for non-vested restricted stock		184	1,083	(1,267)
Stock issued for non-vested restricted stock (in shares)		55
Cash dividends, $0.21 and $0.20 per share for the three months ended March 31, 2014 and 2013 respectively	(2,792)			(2,792)
Shares repurchased or cancelled	(286)	(51)	(296)	61
Shares repurchased or cancelled (in shares)		(15)
Balance at Mar. 31, 2013	208,897	7,416	19,118	177,420	4,943
Balance (in shares) at Mar. 31, 2013		13,958
Balance at Dec. 31, 2013	229,444	9,581	33,255	188,825	(2,217)
Balance (in shares) at Dec. 31, 2013		14,609
Increase (Decrease) in Stockholders' Equity
Net income	8,177			8,177
Other comprehensive income (loss), net of tax	2,047				2,047
Stock compensation expense	290		290
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards	653	75	601	(23)
Stock issued for exercise of stock options and dividend reinvestment plan, net of withholdings to satisfy employee tax obligations upon vesting of stock awards (in shares)		22
Stock issued for non-vested restricted stock		160	987	(1,147)
Stock issued for non-vested restricted stock (in shares)		48
Cash dividends, $0.21 and $0.20 per share for the three months ended March 31, 2014 and 2013 respectively	(3,075)			(3,075)
Shares repurchased or cancelled	(560)	(67)	(519)	26
Shares repurchased or cancelled (in shares)		(20)
Balance at Mar. 31, 2014	$ 236,976	$ 9,749	$ 34,614	$ 192,783	$ (170)
Balance (in shares) at Mar. 31, 2014		14,659