Accumulated Other Comprehensive Income Reclassifications out of Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Income tax expense	$ (276)	$ 286	$ (17)	$ 2,375
Total, net of tax	(1,773)	(4,006)	(5,842)	3,773
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Total, net of tax	(21)	(185)	(466)	(2,140)
Unrealized gains (losses) on available for sale securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net realized gains on sale of securities	(34)	(50)	(754)	(2,773)
Income tax expense	13	19	288	1,094
Total, net of tax	(21)	(31)	(466)	(1,679)
Defined benefit plan items [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Personnel expense	0	(249)	0	(762)
Income tax expense	0	95	0	301
Total, net of tax	$ 0	$ (154)	$ 0	$ (461)