Accumulated Other Comprehensive Loss Reclassification Adjustments (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
Amounts reclassified from AOCI	$ (34)			$ 339
Interest Rate Swaps [Member]
Amounts reclassified from AOCI	(52)		(51)	(109)		(111)
Derivatives, reclassification adjustment for amounts recognized in net income, tax	(28)		(27)	(58)		(60)
Pension Benefits [Member]
Net actuarial loss amortization (net of tax of $282 and $564, respectively)	524	[1]	3,600	1,049	[1]	6,935
Net actuarial loss amortization, tax	282	[1]	1,940	564	[1]	4,132
Net prior service benefit amortization (net of tax of $(34) and $(67), respectively)	(61)	[1]	(67)	(124)	[1]	(130)
Net prior service benefit amortization, tax	(34)	[1]	(36)	(67)	[1]	(77)
Amounts reclassified from AOCI	463			925
Available-for-sale Securities [Member]
Unrealized gain on securities, net (net of tax of $(237) and $(255), respectively)	(445)		(71)	(477)		(127)
Available for sale securities, reclassification adjustment for amounts recognized in net income, tax	$ (237)		$ (35)	$ (255)		$ (65)

[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).