Loans and allowance for loan losses (Details) (USD $)
Sep. 30, 2012
Dec. 31, 2011
Sep. 30, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans $ 374,350,768 $ 427,870,716 $ 436,063,963
Deferred fees and costs 776,064 767,775  
Allowance for loan losses (12,055,844) (16,071,424)  
Loans, net 363,070,988 412,567,067  
Percentage of class of loans to loan portfolio 100.00% 100.00%  
Commercial [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 48,415,814 72,620,537  
Percentage of class of loans to loan portfolio 13.00% 17.00%  
Residential [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 4,937,958 7,906,465  
Percentage of class of loans to loan portfolio 1.00% 2.00%  
Total construction and land development [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 53,353,772 80,527,002  
Percentage of class of loans to loan portfolio 14.00% 19.00%  
Farmland [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 2,591,277 2,464,981 2,026,014
Percentage of class of loans to loan portfolio 1.00% 1.00%  
Commercial real estate - owner occupied [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 97,186,946 105,592,148 103,572,596
Percentage of class of loans to loan portfolio 25.00% 24.00%  
Commercial real estate - non-owner occupied [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 55,294,339 54,059,149 54,463,355
Percentage of class of loans to loan portfolio 15.00% 13.00%  
Multifamily [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 7,569,039 6,679,328 6,746,019
Percentage of class of loans to loan portfolio 2.00% 2.00%  
Total commercial real estate [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 162,641,601 168,795,606  
Percentage of class of loans to loan portfolio 43.00% 39.00%  
Home equity lines [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 26,711,988 30,687,226 32,950,237
Percentage of class of loans to loan portfolio 7.00% 7.00%  
Secured by 1-4 family residential, secured by first deeds of trust [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 82,486,809 93,218,798 94,589,607
Percentage of class of loans to loan portfolio 22.00% 22.00%  
Secured by 1-4 family residential, secured by second deeds of trust [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 9,892,494 12,042,063 12,495,122
Percentage of class of loans to loan portfolio 3.00% 3.00%  
Total consumer real estate [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 119,091,291 135,948,087  
Percentage of class of loans to loan portfolio 32.00% 32.00%  
Commercial and industrial loans (except those secured by real estate) [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans 35,966,193 37,734,516 37,961,852
Percentage of class of loans to loan portfolio 10.00% 9.00%  
Consumer and other [Member]
     
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Total loans $ 3,297,911 $ 4,865,505 $ 4,791,717
Percentage of class of loans to loan portfolio 1.00% 1.00%