Loans - Composition of Loan Portfolio (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	$ 850,018,247	$ 748,023,901
Loans receivable, allowance	9,550,768	9,139,488
Loans receivable, net	840,467,479	738,884,413
Real Estate
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	611,661,482	527,684,178
Real Estate \| SBA Loans—Real Estate
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	121,833,439	106,924,278
Real Estate \| Commercial Real Estate
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	489,828,043	420,759,900
SBA Loans—Non-Real Estate
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	10,671,293	8,634,879
Commercial and Industrial
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	104,301,404	103,681,574
Home Mortgage
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	120,261,899	104,067,756
Consumer
Loans And Leases Receivable Disclosure [Line Items]
Gross loans receivable	$ 3,122,169	$ 3,955,514

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 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 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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