Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Net income (loss)	$ 963	$ (17,851)
Adjustments to reconcile net income (loss) to net cash used in operating activities
Depreciation and amortization	355	1,173
Net (gain) loss on sale or disposal of assets	(3,367)	1,118
Stock-based compensation	381	897
Long-lived asset impairment charge		5,051
Changes in operating assets and liabilities:
Accounts receivable	(15)	1,867
Inventories	900	4,970
Other inventory supplies	76	605
Prepaid expenses and other assets	161	978
Accounts payable	(182)	(369)
Accrued payroll	(73)	(85)
Corporate income and franchise taxes	(8)	(273)
Accrued real estate taxes	(153)	8
Advance payments	(20)	36
Accrued and other current liabilities	(84)	(159)
Net cash used in operating activities	(1,066)	(2,034)
Cash flows from investing activities
Purchases of assets	(2,280)
Proceeds from sale or disposal of assets	11,016	2,561
Purchase of investments	(8,106)	(6,498)
Proceeds from sale of investments	201	57
Net cash (used in) provided by investing activities	831	(3,880)
Cash flows from financing activities
Taxes paid related to net share settlement of equity awards	(14)	(189)
Purchases of treasury stock	(65)
Net cash used in financing activities	(79)	(189)
Net effect of currency translation	(1)	(7)
Net decrease in cash, equivalents and restricted cash	(315)	(6,110)
Cash and cash equivalents, beginning of year	11,725	17,835
Cash and cash equivalents, end of year	11,410	11,725
Supplemental disclosure of cash flow information
Cash paid for interest