Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 22,744	$ 24,353
Restricted cash	196	183
Short-term investments	13,208	20,562
Accounts receivable, net	7,944	8,323
Inventories	22,116	22,739
Other inventory supplies	7,206	8,208
Prepaid expenses and other current assets	838	1,035
Total current assets	74,252	85,403
Property and equipment, net	101,394	107,676
Other assets	1,696	1,827
Total assets	177,342	194,906
Liabilities and stockholders' equity
Accounts payable	2,495	3,754
Accrued payroll	563	514
Accrued and other current liabilities	866	925
Corporate income and franchise taxes	138	270
Accrued real estate taxes	299	280
Advance payments	23	10
Total current liabilities	4,384	5,753
Deferred tax liability	672	593
Total liabilities	$ 5,056	$ 6,346
Commitments and contingencies
Stockholders' equity
Preferred stock, $0.001 par value, 5,000,000 undesignated shares authorized, no shares issued or outstanding
Common stock, $0.001 par value, 40,000,000 shares authorized and 27,978,379 and 27,913,788 shares issued; 26,203,535 and 26,138,944 shares outstanding	$ 28	$ 28
Additional paid-in capital	372,963	372,319
Treasury stock, at cost, 1,774,844 shares	(12,148)	(12,148)
Accumulated other comprehensive loss	(33)	(43)
Accumulated deficit	(188,524)	(171,596)
Total stockholders' equity	172,286	188,560
Total liabilities and stockholders' equity	$ 177,342	$ 194,906