Statement of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Income	$ 22,179	$ 21,933	$ 21,892
Unrealized Securities Holding (Losses) Gains Arising During the Period	(661)	4,741	1,514
Reclassification Adjustment for Net Securities Gains Included in Net Income, Net of Tax	(522)	(1,688)	(910)
Net Retirement Plan Loss	(1,340)	(3,701)	(1,093)
Net Retirement Plan Prior Service (Cost) Credit, Net of Tax	(245)	(161)	146
Amortization of Net Retirement Plan Actuarial Loss, Net of Tax	1,013	602	672
Accretion of Net Retirement Plan Prior Service Credit, Net of Tax	(12)	(65)	(112)
Other Comprehensive (Loss) Income	(1,767)	(272)	217
Comprehensive Income (Loss), Net of Tax	$ 20,412	$ 21,661	$ 22,109