Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income (loss)	$ (1,147)	$ 963
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization	169	355
Net (gain) loss on sale or disposal of assets	(577)	(3,367)
Unrealized (gain) loss on equity investments	171
Stock-based compensation	523	381
Changes in operating assets and liabilities:
Accounts receivable	(320)	(15)
Inventories	(48)	900
Other inventory supplies	42	76
Prepaid expenses and other assets	(380)	161
Accounts payable	332	(182)
Accrued payroll	25	(73)
Corporate income and franchise taxes	(7)	(8)
Accrued real estate taxes	11	(153)
Advance payments	(22)	(20)
Accrued and other current liabilities	(2)	(84)
Net cash used in operating activities	(1,230)	(1,066)
Cash flows from investing activities
Purchases of assets	(64)	(2,280)
Proceeds from sale or disposal of assets	765	11,016
Purchase of investments	(1,575)	(8,106)
Proceeds from sale of investments	304	201
Net cash (used in) provided by investing activities	(570)	831
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(194)	(14)
Purchases of treasury stock	(536)	(65)
Net cash used in financing activities	(730)	(79)
Net effect of currency translation		(1)
Net decrease in cash, cash equivalents and restricted cash	(2,530)	(315)
Cash, cash equivalents and restricted cash, beginning of year	11,410	11,725
Cash, cash equivalents and restricted cash, end of year	$ 8,880	$ 11,410