Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Accumulated Other Comprehensive Income (Loss) [Abstract]
Net unrealized gain on securities available for sale, gross	$ 8,528	$ 7,202	$ 7,270
Net unrealized gain on securities available for sale, tax	3,181	2,688	2,712
Net unrealized gain on securities available for sale, net	5,347	4,514	4,558
Net unrealized loss on other-than-temporarily impaired securities available for sale, gross	(2,282)	(2,318)	(2,441)
Net unrealized loss on other-than-temporarily impaired securities available for sale, tax	(851)	(865)	(910)
Net unrealized loss on other-than-temporarily impaired securities available for sale, net	(1,431)	(1,453)	(1,531)
Net unamortized pension costs, gross	(3,204)	(4,272)	(2,447)
Net unamortized pension costs, tax	(1,195)	(1,593)	(913)
Net unamortized pension costs, net	(2,009)	(2,679)	(1,534)
Net unrealized loss on cash flow hedge, gross	(2,349)	(1,834)	103
Net unrealized loss on cash flow hedge, tax	(876)	(684)	39
Net unrealized (loss) gain on cash flow hedge, net	(1,473)	(1,150)	64
Accumulated other comprehensive income (loss), gross	693	(1,222)	2,485
Accumulated other comprehensive income (loss), tax	259	(454)	928
Accumulated other comprehensive income (loss), net	$ 434	$ (768)	$ 1,557