Consolidated Balance Sheets (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Current assets:    
Cash and cash equivalents $ 23,122 $ 7,599
Marketable securities available-for-sale 166,254 117,531
Accounts receivable 1,627 1,005
Prepaid expenses and other current assets 1,375 2,052
Total current assets 192,378 128,187
Property and equipment, net 8,706 7,965
Goodwill 2,579 2,475
Restricted cash 662 652
Other assets 297 473
Total assets 204,622 139,752
Current liabilities:    
Accounts payable 1,901 2,166
Accrued liabilities 8,166 10,063
Deferred revenues 6,125 6,785
Total current liabilities 16,192 19,014
Deferred revenues, net of current portion 1,173 5,283
Other long-term liabilities 963 629
Total liabilities 18,328 24,926
Commitments and contingencies (Note 9)      
Stockholders’ equity:    
Preferred stock      
Common stock: $0.001 par value; 350,000 and 250,000 shares authorized at December 31, 2013 and 2012, respectively; 262,796 and 182,792 shares issued and outstanding at December 31, 2013 and 2012, respectively 263 183
Additional paid-in capital 688,390 550,729
Total accumulated other comprehensive loss (148) (595)
Accumulated deficit (502,211) (435,491)
Total stockholders’ equity 186,294 114,826
Total liabilities and stockholders’ equity 204,622 139,752
Series B Convertible Preferred Stock
    
Stockholders’ equity:    
Preferred stock