Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) - USD ($)	Class A Common Stock	Class C Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings	Treasury Stock	Total
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2018	$ 30,609,596	$ 4,387,286	$ 41,821,778	$ (2,823)	$ 95,201,732	$ (206,396)	$ 171,811,173
Net earnings	0	0	0	0	1,930,318	0	1,930,318
Other comprehensive loss	0	0	0	820	0	0	820
Stock-based compensation expense	0	0	64,704	0	0	0	64,704
Exercise of stock options	8,936	0	8,444	0	0	0	17,380
Sale of treasury stock	0	0	295,153	0	0	42,343	337,496
Purchase of treasury stock	0	0	0	0	0	(112,404)	(112,404)
Stock dividends	282	(4)	489	0	(769)	0	(2)
Conversion Class C to Class A	6,560	(6,560)	0	0	0	0	0
Stockholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2019	30,625,374	4,380,722	42,190,568	(2,003)	97,131,281	(276,457)	174,049,485
Stockholders' Equity Attributable to Parent, Beginning Balance at Dec. 31, 2019	32,215,558	5,001,774	46,091,112	13,726,514	101,256,229	(1,580,582)	196,710,605
Net earnings	0	0	0	0	1,424,449	0	1,424,449
Other comprehensive loss	0	0	0	(8,852,313)	0	0	(8,852,313)
Stock-based compensation expense	0	0	65,877	0	0	0	65,877
Exercise of stock options	44,822	0	(33,930)	0	0	0	10,892
Sale of treasury stock	0	0	218,280	0	0	264,081	482,361
Purchase of treasury stock	0	0	0	0	0	(129,608)	(129,608)
Stock dividends	2,322	(1,020)	2,292	0	(3,594)	0	0
Conversion Class C to Class A	22,324	(22,324)	0	0	0	0	0
Stockholders' Equity Attributable to Parent, Ending Balance at Mar. 31, 2020	$ 32,285,026	$ 4,978,430	$ 46,343,631	$ 4,874,201	$ 102,677,084	$ (1,446,109)	$ 189,712,263