Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 3,158	$ 3,103
Marketable securities- unrestricted	21,898	26,229
Marketable securities- restricted	10,342	1,026
Inventories	799	897
Prepaid expenses and other current assets	257	531
Total current assets	36,454	31,786
Property and equipment, net	5,327	5,276
Patent and trademark rights, net	947	863
Marketable securities - unrestricted	0	1,958
Marketable securities - restricted	0	2,075
Construction in progress	5,785	1,484
Other assets	65	71
Total assets	48,578	43,513
Current liabilities:
Accounts payable	2,344	1,681
Accrued expenses	1,636	1,644
Margin account loan	5,761	1,695
Current portion of capital lease	49	49
Total current liabilities	9,790	5,069
Long-term liabilities:
Long-term portion of capital lease	64	99
Redeemable warrants	2,112	380
Total liabilities	11,966	5,548
Commitments and contingencies
Stockholders' equity:
Preferred stock, par value $0.01 per share, authorized 5,000,000; issued and outstanding; none	0	0
Common stock, par value $0.001 per share, authorized 350,000,000 shares; issued and outstanding 147,508,498 and 135,642,303, respectively	148	136
Additional paid-in capital	274,671	264,958
Accumulated other comprehensive income (loss)	428	(389)
Accumulated deficit	(238,635)	(226,740)
Total stockholders' equity	36,612	37,965
Total liabilities and stockholders' equity	$ 48,578	$ 43,513