Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets
Cash and cash equivalents	$ 11,241	$ 11,544
Restricted cash	169	181
Short-term investments	14,356	6,451
Accounts receivable, net	733	718
Inventories	2,130	3,030
Other inventory supplies	183	837
Prepaid expenses and other current assets	109	270
Assets held for sale	4,145	11,202
Total current assets	33,066	34,233
Property and equipment, net	2,728	815
Total assets	35,794	35,048
Liabilities and stockholders' equity
Accounts payable	400	582
Accrued payroll	28	101
Accrued and other current liabilities	345	430
Corporate income and franchise taxes	286	294
Accrued real estate taxes	96	249
Advance payments	39	59
Total current liabilities	1,194	1,715
Stockholders' equity
Preferred stock, $0.001 par value, 1,000,000 undesignated shares authorized, no shares issued or outstanding
Common stock, $0.001 par value 8,200,000 shares authorized; 2,919,542 and 2,910,334 shares issued; 2,733,601 and 2,732,850 shares outstanding	29	29
Additional paid-in capital	375,979	375,611
Treasury stock, at cost, 185,941 and 177,484 shares	(12,213)	(12,148)
Accumulated other comprehensive loss	(2)	(3)
Accumulated deficit	(329,193)	(330,156)
Total stockholders' equity	34,600	33,333
Total liabilities and stockholders' equity	$ 35,794	$ 35,048