Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Common Stock [Member] Common Class A [Member]	Common Stock [Member] Common Class B [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2017	$ 2,246,367	$ 710,272	$ 1,741,901	$ (264,841)	$ 5,964,082	$ 10,397,781
Share-based compensation expense	394,933					394,933
Proceeds from sale of business				(1,640,939)		(1,640,939)
Net Income					3,613,710	3,613,710
Balance at Dec. 31, 2018	2,641,300	710,272	1,741,901	(1,905,780)	9,577,792	12,765,485
Share-based compensation expense	223,859					223,859
Net Income					1,745,458	1,745,458
Cumulative effect of accounting change					(73,126)	(73,126)
Balance at Mar. 31, 2019	$ 2,865,159	$ 710,272	$ 1,741,901	$ (1,905,780)	$ 11,250,124	$ 14,661,676