Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013	Jun. 30, 2012
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
INCOME BEFORE PROVISION FOR INCOME TAXES	$ 7,283		$ 8,171		$ 14,703	$ 15,710
Provision for Income Taxes	2,076		2,577		4,315	4,828
Net Income	5,207		5,594		10,388	10,882
Total Reclassifications for the period, net of tax	(228)		(138)		(146)	(59)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available for Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification Adjustment for Securities Gains Included in Net Income, Before-Tax Amount	13		143		540	645
INCOME BEFORE PROVISION FOR INCOME TAXES	13		143		540	645
Provision for Income Taxes	(5)		(57)		(214)	(256)
Net Income	8		86		326	389
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of Defined Benefit Pension Items, Prior-Service Costs, Before Tax	0	[1]	8	[1]	0	15
Amortization of Net Retirement Plan Actuarial Loss, Before-Tax Amount	(392)	[1]	(379)	[1]	(783)	(757)
INCOME BEFORE PROVISION FOR INCOME TAXES	(392)		(371)		(783)	(742)
Provision for Income Taxes	156		147		311	294
Net Income	$ (236)		$ (224)		$ (472)	$ (448)

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see pension footnote for additional details.).