Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
REVENUES	$ 28,140,000	$ 31,162,000
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember
Costs and expenses:
Manufacturing cost of sales	$ 18,069,000	$ 20,233,000
Engineering, selling and administrative	10,857,000	9,514,000
OPERATING (LOSS) INCOME	(786,000)	1,415,000
Other income (expense):
Interest expense, net	(11,000)	(11,000)
Gain (loss) on equity investment in unconsolidated subsidiary	59,453,000	(262,000)
Realized (loss) income on marketable securities	(16,962,000)	74,000
Unrealized (loss) gain on marketable securities	(22,949,000)	139,000
Other income (expense), net	11,000	(51,000)
Total other income (expense), net	19,542,000	(111,000)
INCOME BEFORE INCOME TAXES	18,756,000	1,304,000
Income tax provision	4,118,000	336,000
NET INCOME	$ 14,638,000	$ 968,000
Basic per share information:
Weighted average number of shares used in basic earnings per share calculation	5,275,374	5,173,430
Basic net income per share	$ 2.77	$ 0.19
Diluted per share information:
Weighted average number of shares used in diluted earnings per share calculation	5,334,087	5,216,859
Diluted net income per share	$ 2.74	$ 0.19