Premises and Equipment - Schedule of Premises and Equipment (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Cost	$ 71,105,000	$ 70,161,000
Accumulated depreciation and amortization	29,256,000	28,041,000
Net Book Value	41,849,000	42,120,000
Depreciation and amortization expense	2,878,237	2,896,688	3,047,164
Land
Property, Plant and Equipment [Line Items]
Cost	11,626,000	11,626,000
Accumulated depreciation and amortization	0	0
Net Book Value	11,626,000	11,626,000
Land and leasehold improvements
Property, Plant and Equipment [Line Items]
Cost	8,199,000	8,169,000
Accumulated depreciation and amortization	3,154,000	2,870,000
Net Book Value	5,045,000	5,299,000
Buildings
Property, Plant and Equipment [Line Items]
Cost	26,588,000	26,302,000
Accumulated depreciation and amortization	7,079,000	6,279,000
Net Book Value	19,509,000	20,023,000
Furniture and equipment
Property, Plant and Equipment [Line Items]
Cost	24,177,000	24,002,000
Accumulated depreciation and amortization	19,023,000	18,892,000
Net Book Value	5,154,000	5,110,000
Construction in progress
Property, Plant and Equipment [Line Items]
Cost	515,000	62,000
Accumulated depreciation and amortization	0	0
Net Book Value	$ 515,000	$ 62,000