Other Comprehensive Income/Loss (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net unrealized gain on securities available-for-sale before tax amount:
Net unrealized holding gain on securities available-for-sale arising during the period	$ (649)		$ 11,242	$ (12,180)
Reclassification adjustment for gain on sales of securities included in net income	(141)		(141)	(2,057)
Net unrealized loss on securities available-for-sale	(790)	(1,984)	11,101	(14,237)
Net actuarial loss adjustment on pension plans and other postretirement benefits before tax amount:
Reclassification adjustment for net actuarial loss included in net income	228	903	685	2,708
Prior service cost adjustment on pension plans and other postretirement benefits before tax amount:
Reclassification adjustment for prior service cost included in net income	47	53	142	159
Total other comprehensive income, before tax amount	(515)	(1,028)	11,928	(11,370)
Net unrealized gain on securities available-for-sale, tax expense:
Net unrealized holding gain on securities available-for-sale arising during the period	229		(3,970)	4,291
Reclassification adjustment for gains included in net income	50		50	725
Net unrealized loss on securities available-for-sale	279	698	(3,920)	5,016
Net actuarial loss adjustment on pension plans and other postretirement benefits, tax expense:
Reclassification adjustment for net actuarial loss included in net income	(81)	(318)	(242)	(954)
Prior service cost adjustment on pension plans and other postretirement benefits, tax expense:
Reclassification adjustment for prior service cost included in net income	(16)	(19)	(50)	(56)
Total other comprehensive income, tax expense	182	361	(4,212)	4,006
Net unrealized gain on securities available-for-sale:
Net unrealized holding gain on securities available-for-sale arising during the period	(420)	(1,286)	7,272	(7,889)
Reclassification adjustment for gains included in net income	(91)		(91)	(1,332)
Net unrealized (loss) gain on securities available-for-sale	(511)	(1,286)	7,181	(9,221)
Reclassification adjustment for net actuarial loss on pension plans and other postretirement benefits included in net income	147	585	443	1,754
Prior service cost adjustment on pension plans and other postretirement benefits:
Reclassification adjustment for prior service cost included in net income	31	34	92	103
Total other comprehensive (loss) income, net of tax	$ (333)	$ (667)	$ 7,716	$ (7,364)