Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 22,130	$ 32,003
Marketable securities	3,005	13,524
Accounts receivable, net of allowances of $460 and $150 at December 31, 2013 and 2012, respectively	5,413	7,545
Inventories	1,487	1,302
Prepaid expenses and other current assets	1,567	5,395
Assets held for sale	2,179	0
Total current assets	35,781	59,769
Restricted cash	711	1,511
Non-current marketable securities	795	3,623
Property and equipment, net	8,446	16,650
Intangible assets, net	9,560	12,934
Goodwill	3,241	3,241
Other non-current assets	306	2,237
Total assets	58,840	99,965
Current liabilities:
Accounts payable	3,961	3,654
Accrued compensation	3,625	3,495
Other accrued liabilities	1,612	6,948
Deferred revenues	2,001	2,186
Total current liabilities	11,199	16,283
Deferred revenues, net of current portion	1,114	1,299
Lease incentive obligation	2,160
Other long-term liabilities	5,044	3,943
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value per share; 5,000 shares authorized at December 31, 2013 and 2012; None issued and outstanding at December 31, 2013 and 2012;	0	0
Common stock, $0.0001 par value per share; 100,000 shares authorized at December 31, 2013 and 2012; 38,351 and 37,692 shares issued and outstanding at December 31, 2013 and 2012, respectively;	4	4
Additional paid-in capital	298,370	294,128
Accumulated other comprehensive loss	(32)	(136)
Accumulated deficit	(256,859)	(215,556)
Total stockholders’ equity	41,483	78,440
Total liabilities and stockholders’ equity	$ 58,840	$ 99,965