Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash Flows From Operating Activities:
Net income	$ 3,625,000	$ 2,633,000
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation	432,000	296,000
Depreciation and amortization	525,000	571,000
Losses from marketable securities	50,000
Equity in income of unconsolidated affiliate	(587,000)	(355,000)
Gain on sale of property		(385,000)
Deferred income taxes	159,000	(378,000)
Changes in assets and liabilities:
Accounts receivable, net	(338,000)	51,000
Accounts receivable, related party	(22,000)	(187,000)
Inventories	371,000	745,000
Prepaid expenses	(1,334,000)	681,000
Accounts payable and accrued liabilities	(881,000)	336,000
Net cash provided by operating activities	2,000,000	4,008,000
Cash Flows From Investing Activities:
Purchase of property and equipment	(606,000)	(1,222,000)
Proceeds from sales of marketable securities	36,000
Proceeds from sale of property		537,000
Net cash used in investing activities	(570,000)	(685,000)
Cash Flows From Financing Activities:
Proceeds from exercise of stock options	394,000	210,000
Repurchase of common stock	(3,580,000)	(4,226,000)
Net cash used in financing activities	(3,186,000)	(4,016,000)
Decrease in cash	(1,756,000)	(693,000)
Cash, beginning of the year	8,763,000	9,456,000
Cash, end of the year	7,007,000	8,763,000
Supplemental disclosure of cash flow information:
Cash paid for income taxes	$ 908,000	$ 1,078,000