Bank Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	$ 16,355,000	$ 15,604,000
Less accumulated depreciation and amortization	(10,103,000)	(9,732,000)
Bank premises and equipment, net	6,252,000	5,872,000
Depreciation and amortization	972,000	1,212,000	1,262,000
Land
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	838,000	838,000
Buildings and improvements
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	3,362,000	3,354,000
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	8,351,000	7,813,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Bank premises and equipment, gross	$ 3,804,000	$ 3,599,000