Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 26,487	$ 22,130
Short-term investments	0	3,005
Accounts receivable, net of allowances of $428 at December 31, 2014 and $460 at December 31, 2013	3,870	5,413
Inventories	1,395	1,487
Prepaid expenses and other assets, current	1,255	1,567
Assets held for sale	0	2,179
Total current assets	33,007	35,781
Restricted cash	711	711
Marketable securities	688	795
Property and equipment, net	3,995	8,446
Intangible assets, net	6,186	9,560
Goodwill	3,241	3,241
Other assets, non-current	294	306
Total assets	48,122	58,840
Current liabilities:
Accounts payable	4,673	3,961
Accrued compensation	2,946	3,625
Other accrued liabilities	2,619	1,612
Deferred revenues	3,497	2,001
Total current liabilities	13,735	11,199
Deferred revenues, net of current portion	3,813	1,114
Other liabilities	4,263	5,044
Commitments and contingencies (Note 15)
Stockholders’ equity:
Preferred stock, $0.0001 par value per share; 5,000 shares authorized, none issued and outstanding	0	0
Common stock, $0.0001 par value per share; 100,000 shares authorized; outstanding: 39,563 at December 31, 2014 and 38,351 at December 31, 2013	4	4
Additional paid-in capital	302,379	298,370
Accumulated other comprehensive loss	(142)	(32)
Accumulated deficit	(275,930)	(256,859)
Total stockholders’ equity	26,311	41,483
Total liabilities and stockholders’ equity	$ 48,122	$ 58,840