Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements (Details)

v2.4.0.6
Fair Value Measurements (Details) (USD $)
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2011
Contingent Warrant Liabilities [Member]
        
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]        
Expected volatility (in hundredths)   40.00%    
Risk free interest rate (in hundredths)       0.40%
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]        
Balance, Beginning   $ 379,000    
Initial fair value of warrants issued   6,390,000    
Reclassification of contingent warrant liability to equity upon exercise of warrants   (14,000)    
Net increase in fair value of contingent warrant liabilities upon revaluation   16,538,000    
Balance, Ending   23,293,000   379,000
Net decrease in fair value of contingent warrant liabilities upon revaluation 500,000   2,900,000  
Contingent Warrant Liabilities [Member] | Maximum [Member]
        
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]        
Expected volatility (in hundredths)       103.20%
Risk free interest rate (in hundredths)   0.70%    
Expected term   4 years 8 months 12 days   3 years 1 month 6 days
Contingent Warrant Liabilities [Member] | Minimum [Member]
        
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]        
Expected volatility (in hundredths)       102.10%
Risk free interest rate (in hundredths)   0.30%    
Expected term   2 years 4 months 24 days   2 years 10 months 24 days
Recurring [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Money market funds   30,036,000 [1]   27,222,000 [1]
U.S. treasury securities   26,992,000 [1]    
Foreign exchange option   591,000   1,202,000
Total Assets   57,619,000   28,424,000
Contingent warrant liabilities   23,293,000   379,000
Recurring [Member] | Level 1 [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Money market funds   30,036,000 [1]   27,222,000 [1]
U.S. treasury securities   26,992,000 [1]    
Foreign exchange option   0   0
Total Assets   57,028,000   27,222,000
Contingent warrant liabilities   0   0
Recurring [Member] | Level 2 [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Money market funds   0 [1]   0 [1]
U.S. treasury securities   0 [1]    
Foreign exchange option   591,000   1,202,000
Total Assets   591,000   1,202,000
Contingent warrant liabilities   0   0
Recurring [Member] | Level 3 [Member]
        
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]        
Money market funds   0 [1]   0 [1]
U.S. treasury securities   0 [1]    
Foreign exchange option   0   0
Total Assets   0   0
Contingent warrant liabilities   $ 23,293,000   $ 379,000
[1] Included in cash and cash equivalents