CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Shares Outstanding [Member]	Additional Paid in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance at beginning at Dec. 31, 2017		$ 37,236,566	$ 8,847,164	$ (2,247,415)	$ (1,071,680)	$ 42,764,635
Balance at beginning (in shares) at Dec. 31, 2017	4,989,279
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			6,922,934			6,922,934
Other comprehensive gain (loss)					(705,525)	(705,525)
Stock option exercises, net of surrenders		214,418		(20,849)		$ 193,569
Stock option exercises, net of surrenders (in shares)	22,550					24,056
Stock-based compensation expense		72,408				$ 72,408
Cash dividends			(3,785,460)			(3,785,460)
Common stock dividend, 10%		9,334,342	(9,334,342)
Common stock dividend, 10% (in shares)	499,088
Balance at ending at Dec. 31, 2018		46,857,734	2,650,296	(2,268,264)	(1,777,205)	45,462,561
Balance at ending (in shares) at Dec. 31, 2018	5,510,917
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			7,318,433			7,318,433
Other comprehensive gain (loss)					2,260,019	2,260,019
Stock option exercises, net of surrenders		195,247		(56,961)		$ 138,286
Stock option exercises, net of surrenders (in shares)	19,084					22,163
Stock-based compensation expense		78,053				$ 78,053
Cash dividends			(4,089,320)			(4,089,320)
Balance at ending at Dec. 31, 2019		47,131,034	5,879,409	(2,325,225)	482,814	$ 51,168,032
Balance at ending (in shares) at Dec. 31, 2019	5,530,001					5,530,001
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income			6,460,631			$ 6,460,631
Other comprehensive gain (loss)					1,187,052	1,187,052
Stock option exercises, net of surrenders		180,849		(63,805)		$ 117,044
Stock option exercises, net of surrenders (in shares)	15,535					19,298
Stock-based compensation expense		92,986				$ 92,986
Repurchase of common shares				(398,868)		(398,868)
Repurchase of common shares (in shares)	(25,067)
Cash dividends			(3,646,521)			(3,646,521)
Balance at ending at Dec. 31, 2020		$ 47,404,869	$ 8,693,519	$ (2,787,898)	$ 1,669,866	$ 54,980,356
Balance at ending (in shares) at Dec. 31, 2020	5,520,469					5,520,469