CONSOLIDATED STATEMENTS OF INCOME - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and fee income
Loans, including fees	$ 13,287,318	$ 12,851,900	$ 11,795,303
Taxable securities	1,585,505	1,297,636	1,376,441
Tax-exempt securities	1,026,513	1,007,438	1,012,638
Other	269,811	138,623	45,566
Total interest and fee income	16,169,147	15,295,597	14,229,948
Interest expense
Deposits	423,857	378,733	401,463
Short-term borrowings	6	7	932
Total interest expense	423,863	378,740	402,395
Net interest income	15,745,284	14,916,857	13,827,553
Provision for loan losses	55,000	570,000	192,500
Net interest income after provision for loan losses	15,690,284	14,346,857	13,635,053
Other income
Service charges and fees	1,135,037	1,061,349	991,007
Mortgage banking income	1,057,457	1,387,740	1,605,676
Gains on sales of securities	45,820	380,904	423,832
Other non-interest income	30,157	31,090	29,443
Total other income	2,268,471	2,861,083	3,049,958
Other expense
Salaries and employee benefits	6,060,831	6,087,929	5,859,203
Net occupancy expense	1,571,076	1,528,048	1,480,606
Other operating expenses	2,517,737	2,639,776	2,168,382
Net other real estate owned expenses	92,652	16,691	5,284
Total other expenses	10,242,296	10,272,444	9,513,475
Income before income tax expense	7,716,459	6,935,496	7,171,536
Income tax expense	2,814,634	1,688,433	2,287,248
Net income	$ 4,901,825	$ 5,247,063	$ 4,884,288
Weighted average shares outstanding
Basic (in shares)	4,973,637	4,935,349	4,912,499
Diluted (in shares)	5,058,352	5,054,114	5,067,085
Basic income per common share (in dollars per share)	$ 0.99	$ 1.06	$ 0.99
Diluted income per common share (in dollars per share)	$ 0.97	$ 1.04	$ 0.96