Quarterly report pursuant to Section 13 or 15(d)

Organization and Summary of Significant Accounting Policies - Additional Information (Details)

v3.2.0.727
Organization and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2015
Jun. 30, 2014
Dec. 31, 2014
Dec. 31, 2013
Debt Instrument [Line Items]        
Net loss $ 11,314 $ 17,952    
Cash used in operations 5,323 8,405    
Accumulated deficit 183,940   $ 172,505  
Cash balance (not less than $9.0 million) 12,394 $ 11,550 $ 18,247 $ 2,279
Hercules Term Loan, Liquidity Covenant        
Debt Instrument [Line Items]        
Cash balance (not less than $9.0 million) $ 9,000