Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Disclosure Other Comprehensive Income Loss Detail [Line Items]
Unrealized holding gains (losses) on available-for-sale securities during the period, pre-tax	$ 2,934		$ (8,924)		$ 7,021		$ (11,458)
Reclassification adjustment for (gains) losses included in net income, pre-tax	(84)	[1]	(242)	[1]	(84)	[1]	(256)	[1]
Net unrealized gains (losses) on available-for-sale securities, pre-tax	2,850		(9,166)		6,937		(11,714)
Unrealized holding gains (losses) on available-for-sale securities during the period, tax	(1,026)		3,123		(2,458)		4,010
Reclassification adjustment for (gains) losses included in net income, tax	29	[1]	85	[1]	29	[1]	90	[1]
Income tax effect	(997)		3,208		(2,429)		4,100
Unrealized holding gains (losses) on available-for-sale securities during the period, after-tax	1,908		(5,801)		4,563		(7,448)
Reclassification adjustment for (gains) losses included in net income, after-tax	(55)	[1]	(157)	[1]	(55)	[1]	(166)	[1]
Net unrealized gains (losses) on available-for-sale securities, after-tax	$ 1,854		$ (5,958)		$ 4,508		$ (7,614)

[1] Pre-tax reclassification adjustments relating to available-for-sale securities are reported in security gains and the tax impact is included in income tax expense on the consolidated statements of income.