Income Taxes (Details 3) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Deferred income tax assets:
Allowance for loan losses	$ 8,103	$ 7,056
Deferred compensation	5,643	5,009
Pension and SERP liability	8,621	7,398
Acquisition premium	541	596
Investments writedown	26	26
Deferred gain	11	31
AMT	1,908	1,049
Other	180	75
Nonaccrual interest	151	727
Gross deferred income tax asset	25,184	21,967
Deferred income tax liabilities:
Depreciation	(36)	(201)
Limited partnerships	(2,722)	(2,667)
Unrealized gain on securities available-for-sale	(7,875)	(5,385)
Gross deferred income tax liability	(10,633)	(8,253)
Deferred income tax asset net	$ 14,551	$ 13,714