Loans and Allowance - Major Categories of Loans (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	$ (3,117,870)	$ (2,972,019)	$ (3,307,920)
Loans and leases receivable, total	273,986,237	270,684,120	249,631,525
Loans Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	278,230,503	274,827,478	254,022,692
Unearned income on loans	(1,126,396)	(1,171,339)	(1,083,247)
Loans and leases receivable, net of deferred income	277,104,107	273,656,139	252,939,445
Allowance for credit losses	(3,117,870)	(2,972,019)	(3,307,920)
Loans and leases receivable, total	273,986,237	270,684,120	249,631,525
Loans Receivable \| Mortgage Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	120,933,420	123,645,939	107,728,972
Loans Receivable \| Mortgage Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	62,601,469	67,195,806	71,381,029
Loans Receivable \| Mortgage Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	7,073,720	6,582,553	3,915,299
Loans Receivable \| Demand and time
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	3,518,752	4,172,747	4,901,107
Loans Receivable \| Installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and leases receivable, gross	$ 84,103,142	$ 73,230,433	$ 66,096,285

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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