Condensed Consolidated Statements of Shareholders' Equity - USD ($)	Common Class A [Member] Common Stock [Member]	Common Class A [Member]	Common Class B [Member] Common Stock [Member]	Common Class B [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2019	$ 5,000		$ 1,000		$ 10,959,000	$ 38,000	$ 1,712,000	$ 100,000	$ 12,815,000
Balance (in Shares) at Dec. 31, 2019	4,990,235		762,612
Consolidated net income							90,000		90,000
Exercise stock options					54,000				54,000
Exercise stock options (in Shares)	45,000
Amortization of stock based compensation					6,000				6,000
Cash dividends							(201,000)		(201,000)
Balance at Mar. 31, 2020	$ 5,000		$ 1,000		11,019,000	38,000	1,601,000	100,000	12,764,000
Balance (in Shares) at Mar. 31, 2020	5,035,235		762,612
Balance at Dec. 31, 2019	$ 5,000		$ 1,000		10,959,000	38,000	1,712,000	100,000	12,815,000
Balance (in Shares) at Dec. 31, 2019	4,990,235		762,612
Other comprehensive loss									(5,000)
Balance at Sep. 30, 2020	$ 5,000		$ 1,000		11,037,000	33,000	1,757,000	100,000	12,933,000
Balance (in Shares) at Sep. 30, 2020	5,040,235		762,612
Balance at Mar. 31, 2020	$ 5,000		$ 1,000		11,019,000	38,000	1,601,000	100,000	12,764,000
Balance (in Shares) at Mar. 31, 2020	5,035,235		762,612
Consolidated net income							119,000		119,000
Other comprehensive loss						(5,000)			(5,000)
Exercise stock options					5,000				5,000
Exercise stock options (in Shares)	5,000
Amortization of stock based compensation					7,000				7,000
Cash dividends							(203,000)		(203,000)
Balance at Jun. 30, 2020	$ 5,000		$ 1,000		11,031,000	33,000	1,517,000	100,000	12,687,000
Balance (in Shares) at Jun. 30, 2020	5,040,235		762,612
Consolidated net income							443,000		443,000
Other comprehensive loss									0
Amortization of stock based compensation					6,000				6,000
Cash dividends							(203,000)		(203,000)
Balance at Sep. 30, 2020	$ 5,000		$ 1,000		11,037,000	33,000	1,757,000	$ 100,000	12,933,000
Balance (in Shares) at Sep. 30, 2020	5,040,235		762,612
Balance at Dec. 31, 2020	$ 5,000		$ 1,000		11,071,000	(66,000)	2,231,000		13,242,000
Balance (in Shares) at Dec. 31, 2020	5,062,235	5,062,235	762,612	762,612
Consolidated net income							337,000		337,000
Other comprehensive loss						(13,000)			(13,000)
Amortization of stock based compensation					8,000				8,000
Cash dividends							(233,000)		(233,000)
Balance at Mar. 31, 2021	$ 5,000		$ 1,000		11,079,000	(79,000)	2,335,000		13,341,000
Balance (in Shares) at Mar. 31, 2021	5,062,235		762,612
Balance at Dec. 31, 2020	$ 5,000		$ 1,000		11,071,000	(66,000)	2,231,000		13,242,000
Balance (in Shares) at Dec. 31, 2020	5,062,235	5,062,235	762,612	762,612
Other comprehensive loss									$ (25,000)
Exercise stock options (in Shares)									41,500
Balance at Sep. 30, 2021	$ 5,000		$ 1,000		11,150,000	(91,000)	3,135,000		$ 14,200,000
Balance (in Shares) at Sep. 30, 2021	5,103,568	5,103,568	762,612	762,612
Balance at Mar. 31, 2021	$ 5,000		$ 1,000		11,079,000	(79,000)	2,335,000		13,341,000
Balance (in Shares) at Mar. 31, 2021	5,062,235		762,612
Consolidated net income							590,000		590,000
Other comprehensive loss						(3,000)			(3,000)
Exercise stock options					46,000				46,000
Exercise stock options (in Shares)	31,333
Amortization of stock based compensation					6,000				6,000
Cash dividends							(233,000)		(233,000)
Balance at Jun. 30, 2021	$ 5,000		$ 1,000		11,131,000	(82,000)	2,692,000		13,747,000
Balance (in Shares) at Jun. 30, 2021	5,093,568		762,612
Consolidated net income							678,000		678,000
Other comprehensive loss						(9,000)			(9,000)
Exercise stock options					10,000				10,000
Exercise stock options (in Shares)	10,000
Amortization of stock based compensation					9,000				9,000
Cash dividends							(235,000)		(235,000)
Balance at Sep. 30, 2021	$ 5,000		$ 1,000		$ 11,150,000	$ (91,000)	$ 3,135,000		$ 14,200,000
Balance (in Shares) at Sep. 30, 2021	5,103,568	5,103,568	762,612	762,612