Consolidated Statements of Stockholders' Equity - USD ($)	Common Stock	Additional Paid in Capital	Retained Earnings	Treasury Stock	Total
Balances at Dec. 31, 2018	$ 7,738	$ 36,302,446	$ 72,176,719	$ (10,898,383)	$ 97,588,520
Balances (in shares) at Dec. 31, 2018	7,738,167
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon stock option exercise	$ 73	2,133,323			2,133,396
Issuance of common stock upon stock option exercise (in shares)	73,063
Stock compensation expense		520,387			520,387
Repurchases of common stock				(357,289)	(357,289)
Net income			17,115,988		17,115,988
Balances at Sep. 30, 2019	$ 7,811	38,956,156	89,292,707	(11,255,672)	117,001,002
Balances (in shares) at Sep. 30, 2019	7,811,230
Balances at Jun. 30, 2019	$ 7,796	38,299,800	83,019,774	(11,016,949)	110,310,421
Balances (in shares) at Jun. 30, 2019	7,796,230
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon stock option exercise	$ 15	396,435			396,450
Issuance of common stock upon stock option exercise (in shares)	15,000
Stock compensation expense		259,921			259,921
Repurchases of common stock				(238,723)	(238,723)
Net income			6,272,933		6,272,933
Balances at Sep. 30, 2019	$ 7,811	38,956,156	89,292,707	(11,255,672)	117,001,002
Balances (in shares) at Sep. 30, 2019	7,811,230
Balances at Dec. 31, 2019	$ 7,813	39,355,797	96,646,527	(11,519,035)	$ 124,491,102
Balances (in shares) at Dec. 31, 2019	7,813,230				7,339,578
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon vesting of restricted stock units	$ 11	(11)
Issuance of common stock upon vesting of restricted stock units (in shares)	11,450
Issuance of common stock upon stock option exercise	$ 2	61,723			$ 61,725
Issuance of common stock upon stock option exercise (in shares)	1,500
Stock compensation expense		1,173,714			1,173,714
Repurchases of common stock				(412,761)	(412,761)
Net income			10,001,209		10,001,209
Balances at Sep. 30, 2020	$ 7,826	40,591,223	106,647,736	(11,931,796)	$ 135,314,989
Balances (in shares) at Sep. 30, 2020	7,826,180				7,344,955
Balances at Jun. 30, 2020	$ 7,826	40,080,279	101,261,129	(11,931,796)	$ 129,417,438
Balances (in shares) at Jun. 30, 2020	7,826,180
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation expense		510,944			510,944
Net income			5,386,607		5,386,607
Balances at Sep. 30, 2020	$ 7,826	$ 40,591,223	$ 106,647,736	$ (11,931,796)	$ 135,314,989
Balances (in shares) at Sep. 30, 2020	7,826,180				7,344,955