Other Comprehensive Income/Loss (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net unrealized loss on securities available-for-sale before tax amount:
Net unrealized holding loss on securities arising during the period	$ (10,396)		$ (10,196)
Reclassification adjustment for gain on sales of securities included in net income	(2,057)		(2,057)
Net unrealized loss on securities available-for-sale	(12,453)		(12,253)
Net unrealized loss on securities available-for-sale, tax benefit (expense):
Net unrealized holding loss on securities arising during the period	3,663		3,593
Reclassification adjustment for gain on sales of securities included in net income	725		725
Net unrealized loss on securities available-for-sale	4,388		4,318
Net unrealized loss on securities available-for-sale:
Net unrealized holding loss on securities arising during the period	(6,733)	1,416	(6,603)	602
Reclassification adjustment for gain on sales of securities included in net income	(1,332)		(1,332)	(1,604)
Net unrealized (loss) gain on securities available-for-sale	(8,065)	1,416	(7,935)	(1,002)
Reclassification adjustment for net actuarial loss included in net income, Before Tax Amount	838		1,805
Reclassification adjustment for net actuarial loss included in net income, Tax Benefit (Expense)	(296)		(636)
Reclassification adjustment for net actuarial loss included in net income, After Tax Amount	542	428	1,169	2,629
Reclassification adjustment for prior service cost included in net income, Before Tax Amount	53		106
Reclassification adjustment for prior service cost included in net income, Tax Benefit (Expense)	(18)		(37)
Reclassification adjustment for prior service cost included in net income, After Tax Amount	35	33	69	35
Other Comprehensive loss, Before Tax Amount	(11,562)		(10,342)
Other Comprehensive loss, Tax Benefit (Expense)	4,074		3,645
Total other comprehensive (loss) income, net of tax	$ (7,488)	$ 1,924	$ (6,697)	$ 22,506