Comprehensive Income Other Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Comprehensive Income [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	$ 220	$ (98)
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	(82)	(79)
Other Comprehensive Income (Loss), before Tax	231	(293)
Other Comprehensive Income (Loss), Tax	(93)	116
Other Comprehensive (Loss) Income	138	(177)
Unrealized Gains and Losses on Available for Sale Securities [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income Loss Before Reclassifications Before Tax	367	(162)
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit	(147)	64
Other comprehensive income (loss), before reclassifications, net of tax	220	(98)
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax	(527)	(502)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	209	199
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	(318)	(303)
Other Comprehensive (Loss) Income	(98)	(401)
Amortization of Net Retirement Plan Actuarial Loss [Member]
Schedule of Comprehensive Income [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	0	0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax	391	378
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	(155)	(150)
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	236	228
Other Comprehensive (Loss) Income	236	228
Accretion of Net Retirement Plan Prior Service Credit [Member]
Schedule of Comprehensive Income [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	0	0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax	0	(7)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	0	3
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	0	(4)
Other Comprehensive (Loss) Income	$ 0	$ (4)