Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets
Cash and cash equivalents	$ 10,326	$ 8,709
Restricted cash		171
Short-term investments	14,745	15,458
Accounts receivable, net	703	1,053
Inventories	1,033	1,710
Other inventory supplies	139	140
Prepaid expenses and other current assets	142	488
Assets held for sale	1,011	3,957
Total current assets	28,099	31,686
Inventories, non-current	468	468
Property and equipment, net	2,524	2,647
Total assets	31,091	34,801
Liabilities and stockholders' equity
Accounts payable	326	733
Accrued payroll	34	53
Accrued and other current liabilities	175	344
Corporate income and franchise taxes	304	296
Accrued real estate taxes	54	114
Advance payments		16
Total current liabilities	893	1,556
Total liabilities	893	1,556
Commitments and contingencies (Note 7)
Stockholders' equity
Preferred stock, $.001 par value, 1,000,000 undesignated shares authorized, no shares issued or outstanding
Common stock, $.001 par value, 8,200,000 shares authorized; 2,958,850 and 2,955,253 shares issued; 2,409,822 and 2,702,171 shares outstanding, respectively	29	29
Additional paid-in capital	376,352	376,306
Treasury stock, at cost, 549,028 and 253,082 shares	(15,148)	(12,749)
Accumulated other comprehensive loss	(1)	(1)
Accumulated deficit	(331,034)	(330,340)
Total stockholders' equity	30,198	33,245
Total liabilities and stockholders' equity	$ 31,091	$ 34,801