Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income (loss)	$ (1,063)	$ (1,147)
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization	167	169
Net (gain) loss on sale or disposal of assets and subsidiary	(2,084)	(577)
Unrealized (gain) loss on equity investments		171
Realized (gain) loss on equity investments	1,824
Stock-based compensation	198	523
Changes in operating assets and liabilities:
Accounts receivable	666	(320)
Inventories	637	(48)
Other inventory supplies		42
Prepaid expenses and other assets	204	(380)
Accounts payable	(236)	332
Accrued payroll	158	25
Corporate income and franchise taxes	9	(7)
Accrued real estate taxes	(42)	11
Advance payments	2	(22)
Accrued and other current liabilities	(143)	(2)
Net provided by (cash used) in operating activities	297	(1,230)
Cash flows from investing activities
Purchases of assets	(2)	(64)
Proceeds from sale or disposal of assets	4,909	765
Proceeds from sale or disposal of subsidiary	744
Purchase of investments	(2,782)	(1,575)
Proceeds from sale of investments	1,667	304
Net cash provided by (used in) provided by investing activities	4,536	(570)
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(48)	(194)
Purchases of treasury stock	(2,399)	(536)
Net cash used in financing activities	(2,447)	(730)
Net effect of currency translation	(136)
Net increase (decrease) in cash, cash equivalents and restricted cash	2,250	(2,530)
Cash, cash equivalents and restricted cash, beginning of year	8,880	11,410
Cash, cash equivalents and restricted cash, end of year	$ 11,130	$ 8,880