Income Taxes - Components of net deferred income tax benefits (Details 2) - USD ($)
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Deferred income tax benefits:      
Accrued deferred compensation $ 153,256 $ 142,308 $ 129,101
Impairment loss on investment securities   1,305,584 1,218,497
Allowance for credit losses 362,732 364,697 458,303
Nonaccrual interest 445,173 445,173 339,765
Alternative minimum tax credits 929,264 615,186 485,444
Net operating loss carryforward credits 373,986    
Accumulated depreciation 61,019 72,354 60,627
Other real estate owned 14,940 14,940 14,940
Reserve for unfunded commitments 4,641 78,890 78,890
Other temporary differences 2,116 2,116 1,332
Accumulated securities premium accretion 138,207 71,834 39,514
Net unrealized depreciation on investment securities available for sale 199,277   778,048
Total deferred income tax benefits $ 2,684,611 $ 3,113,082 $ 3,604,461
Deferred income tax liabilities:      
Accumulated securities discount accretion
Net unrealized appreciation on investment securities available for sale   $ 67,847  
Total deferred income tax liabilities   67,847  
Net deferred income tax benefits $ 2,684,611 $ 3,045,235 $ 3,604,461