Bank Premises, Equipment and Leases - Schedule of Premises, Equipment and Leases (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 34,341	$ 33,755
Less: accumulated depreciation and amortization	25,620	24,787
Net bank premises and equipment	8,721	8,968
Depreciation and amortization	1,147	1,228	1,357
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,452	2,452
Premises and Equipment
Property, Plant and Equipment [Line Items]
Depreciation and amortization	887	1,032	1,121
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,373	11,406
Equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	14,706	14,514
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,088	1,088
Purchased Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,722	4,295
Depreciation and amortization	$ 260	$ 196	$ 236