Comprehensive Income (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Components of accumulated other comprehensive income
Net unrealized gains on available-for-sale securities	$ 7,361	$ 8,434
Tax effect	(3,095)	(3,547)
Unrealized gains on available-for-sale securities, net of tax	4,266	4,887
Minimum pension liability	(3,806)	(3,806)
Tax effect	1,600	1,600
Minimum pension liability, net of tax	(2,206)	(2,206)
Joint beneficiary agreement liability	(522)	(522)
Tax effect
Joint beneficiary agreement liability, net of tax	(522)	(522)
Accumulated other comprehensive income, net of tax	$ 1,538	$ 2,159