CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income
Beginning Balance at Dec. 31, 2012	$ 233,815	$ 49,667	$ 181,151	$ 2,997
Beginning Balance (in shares) at Dec. 31, 2012		7,622,750
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	11,993		11,993
Other comprehensive loss, net of tax	(12,293)			(12,293)
Stock-based compensation expense	159	159
Exercise of stock options and issuance of vested share awards, net of repurchase for tax withholdings and tax benefit		17,962
Exercise of stock options and issuance of vested share awards, net of repurchase for tax withholdings and tax benefit (shares)	83	83
Cash dividends declared ($0.54 and $0.54 per share)	(4,137)		(4,137)
Ending Balance at Jun. 30, 2013	229,620	49,909	189,007	(9,296)
Ending Balance (in shares) at Jun. 30, 2013		7,640,712
Beginning Balance at Dec. 31, 2013	231,096	47,783	195,660	(12,347)
Beginning Balance (in shares) at Dec. 31, 2013		7,579,913
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	12,031		12,031
Other comprehensive loss, net of tax	5,173			5,173
Stock-based compensation expense	431	431
Exercise of stock options and issuance of vested share awards, net of repurchase for tax withholdings and tax benefit		22,887
Exercise of stock options and issuance of vested share awards, net of repurchase for tax withholdings and tax benefit (shares)	152	152
Common stock repurchased (in shares)		(181,355)
Common stock repurchased	(7,155)	(7,155)
Cash dividends declared ($0.54 and $0.54 per share)	(4,008)		(4,008)
Ending Balance at Jun. 30, 2014	$ 237,720	$ 41,211	$ 203,683	$ (7,174)
Ending Balance (in shares) at Jun. 30, 2014		7,421,445