Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net income (loss)	$ (1,132)	$ 820
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization	127	309
Net gain on sale or disposal of assets	(273)	(2,738)
Stock-based compensation	525	359
Changes in operating assets and liabilities:
Accounts receivable	388	(68)
Inventories	332	468
Other inventory supplies	39	74
Prepaid expenses and other assets	(3)	130
Accounts payable	(143)	(321)
Accrued payroll	43	(21)
Accrued real estate taxes	(9)	(206)
Corporate income and franchise taxes	2	(15)
Advanced payments	(16)	(18)
Accrued and other current liabilities	(36)	(145)
Net cash used in operating activities	(156)	(1,372)
Cash flows from investing activities
Purchase of property and equipment	(64)	(2,280)
Proceeds from sale or disposal of assets	273	10,387
Purchases of investments	(1,606)	(8,314)
Proceeds from sale of investments	536	184
Net cash used in investing activities	(861)	(23)
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(7)	(9)
Purchases of common stock	(501)
Net cash used in financing activities	(508)	(9)
Net effect of currency translation
Net decrease in cash, cash equivalents and restricted cash	(1,525)	(1,404)
Cash, cash equivalents and restricted cash, beginning of period	11,410	11,725
Cash, cash equivalents and restricted cash, end of period	$ 9,885	$ 10,321