Consolidated Statements of Comprehensive Income (Loss) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 5,117	$ 4,987	$ 9,824	$ 9,424
Other comprehensive income:
Unrealized loss on securities (net of tax benefit of $209 and $286 in 2014 and $3,900 and $3,361 in 2013)	(303)	(5,646)	(414)	(4,866)
Accretion of unrealized loss on securities reclassified to held-to-maturity (net of tax expense of $125 and $233 in 2014)	181	0	337	0
Reclassification adjustment for gains included in net income (net of tax expense of $142 in 2014 and $17 in 2013)	(206)	(25)	(206)	(25)
Total comprehensive income (loss)	$ 4,789	$ (684)	$ 9,541	$ 4,533