CONDENSED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Current assets:
Cash	$ 1,287	$ 1,854
Investments available for sale	28,292	32,238
Accounts receivable, net	5,346	3,063
Inventory	1,611	1,278
Prepaid expenses and other current assets	462	603
Total current assets	36,998	39,036
Property and equipment, net	2,037	2,111
Restricted cash	317	317
Total assets	39,352	41,464
Current liabilities:
Accounts payable and accrued expenses	4,985	4,999
Capital lease obligations, current portion	44	44
Total current liabilities	5,029	5,043
Long-term portion of capital lease obligations	151	162
Other long-term liabilities	350	369
Total liabilities	5,530	5,574
Stockholders' equity
Common stock, $.001 par value, 90,000 shares authorized, 32,930 shares outstanding - 2013, 32,881 shares outstanding - 2012	33	33
Additional paid-in-capital	279,911	279,269
Accumulated other comprehensive income (loss)	5	(20)
Accumulated deficit	(246,127)	(243,392)
Total stockholders' equity	33,822	35,890
Total liabilities and stockholders' equity	$ 39,352	$ 41,464