Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Net Income	$ 5,623		$ 5,748		$ 16,011		$ 16,630
Other comprehensive income (loss), before reclassifications, net of tax	1,210	[1]	411	[1]	(2,213)	[1]	758	[1]
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	236	[1]	185	[1]	382	[1]	244	[1]
Other Comprehensive Income (Loss)	1,446		596		(1,831)		1,002
Comprehensive Income	7,069		6,344		14,180		17,632
Unrealized Gains and Losses on Available for Sale Securities [Member]
Other comprehensive income (loss), before reclassifications, net of tax	1,210	[1]	411	[1]	(2,213)	[1]	758	[1]
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	0	[1]	(39)	[1]	(326)	[1]	(428)	[1]
Amortization of Net Retirement Plan Actuarial Loss [Member]
Other comprehensive income (loss), before reclassifications, net of tax	0	[1]	0	[1]	0	[1]	0	[1]
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	235	[1]	228	[1]	707	[1]	685	[1]
Accretion of Net Retirement Plan Prior Service Credit [Member]
Other comprehensive income (loss), before reclassifications, net of tax	0	[1]	0	[1]	0	[1]	0	[1]
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	$ 1	[1]	$ (4)	[1]	$ 1	[1]	$ (13)	[1]

[1] (1) All amounts are net of tax. Amounts in parentheses indicate debits.