Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Common Stock Including Additional Paid in Capital [Member] Common Class A [Member]	Common Stock Including Additional Paid in Capital [Member] Common Class B [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member] Common Class A [Member]	Treasury Stock [Member] Common Class B [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Common Stock Outstanding [Member] Common Class A [Member]	Common Stock Outstanding [Member] Common Class B [Member]	Total
Balance at Dec. 31, 2019	$ 3,599,806	$ 1,465,522	$ 1,741,901			$ (1,905,780)	$ 16,527,083			$ 21,428,532
Share-based compensation expense	70,849									70,849
Stock awards	226,050									226,050
Repurchase of shares						(32,272)				(32,272)
Net income							5,839,387			5,839,387
Balance at Dec. 31, 2020	$ 3,896,705	$ 1,465,522	1,741,901			(1,938,052)	22,366,470			27,532,546
Balance (in shares) at Dec. 31, 2019	2,576,837	954,283		37,208	182,435			2,539,629	771,848
Stock awards (in shares)	17,250							17,250
Stock option exercise (in shares)	1,000							1,000
Repurchase of shares (in shares)				2,259				(2,259)
Balance (in shares) at Dec. 31, 2020	2,595,087	954,283		39,467	182,435			2,555,620	771,848
Share-based compensation expense	$ 15,667									15,667
Stock awards	313,961									313,961
Repurchase of shares						(41,033)				(41,033)
Net income							3,143,417			3,143,417
Issuance for acquisition	1,059,000									1,059,000
Balance at Mar. 31, 2021	$ 5,285,333	$ 1,465,522	$ 1,741,901			$ (1,979,085)	$ 25,509,887			$ 32,023,559
Stock awards (in shares)	23,700							23,700
Repurchase of shares (in shares)				2,262				(2,262)
Acquisition (in shares)	60,000							60,000
Balance (in shares) at Mar. 31, 2021	2,678,787	954,283		41,729	182,435			2,637,058	771,848