Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
The components of accumulated other comprehensive income (loss):
Unrealized gain (loss) on securities available for sale	$ 2,982	$ 3,290	$ 4,161
Deferred tax asset (liability)	(1,163)	(1,283)	(1,624)
Net unrealized gain (loss) on securities available for sale	1,819	2,007	2,537
Additional pension liability	(3,576)	(3,579)	(17,968)
Deferred tax asset	1,395	1,396	7,099
Net additional pension liability	(2,181)	(2,183)	(10,869)
Total accumulated other comprehensive income (loss)	$ (362)	$ (176)	$ (8,332)