Fair Value of Financial Instruments - Carrying Value and Estimated Fair Value of Financial Instruments (Detail) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Financial assets
Cash and due from banks	$ 24,334,437	$ 14,947,690
Interest bearing deposits with banks	17,457,142	42,267,777
Securities held-to-maturity	84,366,086	169,045,835
Securities available-for-sale	435,785,417	267,264,403
Net loans	399,100,065	425,096,569
Financial liabilities
Deposits	779,786,905	753,530,743
Federal Home Loan Bank advances	20,532,937	20,534,935
Securities Sold under Agreement to Repurchase	112,829,476	104,298,182
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets
Cash and due from banks	24,334,437	14,947,690
Interest bearing deposits with banks	17,457,142	42,267,777
Financial liabilities
Deposits	577,145,059	542,640,313
Securities Sold under Agreement to Repurchase	112,829,476	104,298,182
Significant Other Observable Inputs (Level 2) [Member]
Financial assets
Securities held-to-maturity	84,366,086	169,045,835
Securities available-for-sale	432,840,724	264,348,694
Significant Unobservable Inputs (Level 3) [Member]
Financial assets
Securities available-for-sale	2,944,693	2,915,709
Net loans	399,100,065	425,096,569
Financial liabilities
Deposits	202,641,846	210,890,430
Federal Home Loan Bank advances	20,532,937	20,534,935
Carrying Value [Member]
Financial assets
Cash and due from banks	24,334,437	14,947,690
Interest bearing deposits with banks	17,457,142	42,267,777
Securities held-to-maturity	78,122,952	161,043,404
Securities available-for-sale	435,785,417	267,264,403
Net loans	397,558,888	423,108,391
Financial liabilities
Deposits	779,658,600	753,404,788
Federal Home Loan Bank advances	20,000,000	20,000,000
Securities Sold under Agreement to Repurchase	$ 112,829,476	$ 104,298,182