Accumulated Other Comprehensive Loss Reclassification Adjustments (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
Amounts reclassified from AOCI	$ 540			$ 879
Interest Rate Swaps [Member]
Amounts reclassified from AOCI	(51)		(48)	(160)		(159)
Derivatives, reclassification adjustment for amounts recognized in net income, tax	(28)		(26)	(86)		(85)
Pension Benefits [Member]
Net actuarial loss amortization (net of tax of $280 and $844, respectively)	526	[1]	1,940	1,575	[1]	8,875
Net actuarial loss amortization, tax	280	[1]	922	844	[1]	5,054
Net prior service benefit amortization (net of tax of $(33) and $(100), respectively)	(62)	[1]	(171)	(186)	[1]	(301)
Net prior service benefit amortization, tax	(33)	[1]	(90)	(100)	[1]	(167)
Amounts reclassified from AOCI	464			1,389
Available-for-sale Securities [Member]
Unrealized gain (loss) on securities, net (net of tax of $67 and $(188), respectively)	127		(1,012)	(350)		(1,139)
Available for sale securities, reclassification adjustment for amounts recognized in net income, tax	$ 67		$ (522)	$ (188)		$ (587)

[1] Pension and other post-retirement benefits AOCI components are included in the computation of net periodic benefit cost (refer to note 12 to the condensed consolidated financial statements).