Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 21,522	$ 22,130
Short-term investments	0	3,005
Accounts receivable, net of allowances of $513 at September 30, 2014 and $460 at December 31, 2013	3,088	5,413
Inventories, net	1,943	1,487
Prepaid expenses and other current assets	1,652	1,567
Assets held for sale	0	2,179
Total current assets	28,205	35,781
Restricted cash	711	711
Marketable securities	1,031	795
Property and equipment, net	4,374	8,446
Intangible assets, net	7,029	9,560
Goodwill	3,241	3,241
Other non-current assets	201	306
Total assets	44,792	58,840
Current liabilities:
Accounts payable	2,542	3,961
Accrued compensation	2,376	3,625
Other accrued liabilities	2,050	1,612
Deferred revenue	4,036	2,001
Total current liabilities	11,004	11,199
Deferred revenue, net of current portion	4,368	1,114
Other long-term liabilities	4,213	5,044
Total liabilities	19,585	17,357
Commitments and contingencies (note 11)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 5,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.0001 par value; 100,000 shares authorized at September 30, 2014 and December 31, 2013; 39,510 and 38,351 shares issued and outstanding at September 30, 2014 and December 31, 2013, respectively	4	4
Additional paid-in capital	301,365	298,370
Accumulated other comprehensive income (loss)	113	(32)
Accumulated deficit	(276,275)	(256,859)
Total stockholders’ equity	25,207	41,483
Total liabilities and stockholders’ equity	$ 44,792	$ 58,840