Consolidated Statements of Income - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest income:
Interest and fees on loans	$ 16,299,091	$ 14,796,649	$ 12,695,520
Interest on debt securities:  Taxable	1,286,473	1,170,259	1,345,549
Interest on debt securities:  Tax-exempt	1,228,479	1,253,064	1,240,706
Dividends	102,360	89,840	72,619
Interest on deposits in other banks	195,032	103,244	62,138
Interest on certificates of deposit in other banks	34,879	52	11,795
Total interest income	19,146,314	17,413,108	15,428,327
Interest expense:
Deposits	1,153,609	935,291	795,850
Federal funds purchased	1,068	10	426
Other short-term borrowings	224,144	103,567	67,274
Long-term debt	523,344	573,225	453,258
Total interest expense	1,902,165	1,612,093	1,316,808
Net interest income	17,244,149	15,801,015	14,111,519
Provision for loan losses	300,000	160,000	141,300
Net interest income after provision for loan losses	16,944,149	15,641,015	13,970,219
Noninterest income:
Service charges on deposit accounts	1,005,270	1,086,268	1,121,240
Income from trust services	218,657	209,755	245,279
Income from brokerage services	362,416	342,051	420,695
Income from insurance services	1,523,309	1,477,663	1,372,872
Income from mortgage banking services	155,053	354,627	317,970
Net gain (loss) on sale or disposition of assets	(9,022)	38,165	22,382
Net gain on sale of securities	186,610	168,919	3,587
Other income	870,229	781,811	756,152
Total noninterest income	4,312,522	4,459,259	4,260,177
Noninterest expense:
Salaries and employee benefits	9,250,777	8,765,865	7,914,155
Occupancy expense	1,124,028	1,140,600	1,120,940
Equipment expense	850,376	860,935	923,267
Data processing expense	1,513,630	1,367,569	1,224,177
Amortization of intangible assets	15,625	15,625	15,625
Other operating expenses	3,074,843	2,763,227	2,831,433
Total noninterest expenses	15,829,279	14,913,821	14,029,597
Income before income taxes	5,427,392	5,186,453	4,200,799
Provision for income taxes	1,619,900	1,152,476	827,164
Net income	$ 3,807,492	$ 4,033,977	$ 3,373,635
Basic earnings per share:
Net income	$ 1.49	$ 1.58	$ 1.32
Weighted average shares outstanding	2,547,421	2,547,778	2,547,837
Diluted earnings per share:
Net income	$ 1.49	$ 1.58	$ 1.32
Weighted average shares outstanding	2,547,422	2,547,778	2,547,837