Comprehensive Income 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
Schedule of Comprehensive Income [Line Items]
Other comprehensive income (loss), before reclassifications, net of tax	$ (3,643)	$ 445	$ (3,423)	$ 347
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	228	138	146	59
Other Comprehensive Income (Loss), before Tax	(5,655)	967	(5,424)	674
Other Comprehensive Income (Loss), Tax	2,240	(384)	2,147	(268)
Other Comprehensive (Loss) Income	(3,415)	583	(3,277)	406
Unrealized Gains and Losses on Available for Sale Securities [Member]
Schedule of Comprehensive Income [Line Items]
Other Comprehensive Income Loss Before Reclassifications Before Tax	(6,034)	739	(5,667)	577
Other Comprehensive Income Loss Before Reclassifications Tax (Expense) Benefit	2,391	(294)	2,244	(230)
Other comprehensive income (loss), before reclassifications, net of tax	(3,643)	445	(3,423)	347
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax	(13)	(143)	(540)	(645)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	5	57	214	256
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	(8)	(86)	(326)	(389)
Other Comprehensive (Loss) Income	(3,651)	359	(3,749)	(42)
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	0	0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax	392	379	783	757
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit	(156)	(150)	(311)	(300)
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	236	229	472	457
Other Comprehensive (Loss) Income	236	229	472	457
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	0	0
Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax		(8)		(15)
Reclassification From Accumulated Other Comprehensive Income Current Period Tax (Expense) Benefit		3		6
Reclassification from Accumulated Other Comprehensive Income, current period, net of tax	0	(5)	0	(9)
Other Comprehensive (Loss) Income	$ 0	$ (5)	$ 0	$ (9)