CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($)	Common Class A [Member]	Additional paid-in capital [Member]	Retained earnings [Member]	Treasury stock [Member]	Accumulated other comprehensive loss [Member]	Total
Balance at Dec. 31, 2019	$ 4,416,000	$ 14,056,000	$ 38,867,000	$ (10,213,000)	$ (620,000)	$ 46,506,000
Balance (in shares) at Dec. 31, 2019	4,416,000			(1,273,000)
Net loss	$ 0	0	(758,000)	$ 0	0	(758,000)
Exercise of stock options	$ 1,000	2,000	0	0	0	3,000
Exercise of stock options (in shares)	1,000
Restricted common stock compensation	$ 0	13,000	0	0	0	13,000
Restricted common stock compensation (in shares)	0
Stock-based compensation	$ 0	16,000	0	0	0	16,000
Dividends	0	0	(157,000)	0	0	(157,000)
Foreign currency translation adjustment	0	0	0	0	(125,000)	(125,000)
Balance at Mar. 31, 2020	$ 4,417,000	14,087,000	37,952,000	$ (10,213,000)	(745,000)	45,498,000
Balance (in shares) at Mar. 31, 2020	4,417,000			(1,273,000)
Balance at Dec. 31, 2020	$ 4,428,000	14,144,000	33,756,000	$ (10,213,000)	(577,000)	41,538,000
Balance (in shares) at Dec. 31, 2020	4,428,000			(1,273,000)
Net loss	$ 0	0	(307,000)	$ 0	0	(307,000)
Restricted common stock compensation	$ 25,000	(12,000)	0	$ 0	0	13,000
Restricted common stock compensation (in shares)	25,000			0
Stock-based compensation	$ 0	2,000	0	$ 0	0	2,000
Foreign currency translation adjustment	0	0	0	0	15,000	15,000
Balance at Mar. 31, 2021	$ 4,453,000	$ 14,134,000	$ 33,449,000	$ (10,213,000)	$ (562,000)	$ 41,261,000
Balance (in shares) at Mar. 31, 2021	4,453,000			(1,273,000)