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 9 Months Ended 12 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 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     (337,000)    
Net increase in fair value of contingent warrant liabilities upon revaluation     25,747,000    
Balance, Ending 32,179,000   32,179,000   379,000
Net decrease in fair value of contingent warrant liabilities upon revaluation 9,200,000 500,000 25,700,000 3,300,000  
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 2 months 12 days   2 years 10 months 24 days
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 4 months 24 days   3 years 1 month 6 days
Recurring [Member]
          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Money market funds 30,841,000 [1]   30,841,000 [1]   27,222,000 [1]
U.S. treasury securities 16,999,000   16,999,000    
Foreign exchange option 481,000   481,000   1,202,000
Total Assets 48,321,000   48,321,000   28,424,000
Contingent warrant liabilities 32,179,000   32,179,000   379,000
Recurring [Member] | Level 1 [Member]
          
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]          
Money market funds 30,841,000 [1]   30,841,000 [1]   27,222,000 [1]
U.S. treasury securities 16,999,000   16,999,000    
Foreign exchange option 0   0   0
Total Assets 47,840,000   47,840,000   27,222,000
Contingent warrant liabilities 0   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]   0 [1]
U.S. treasury securities 0   0    
Foreign exchange option 481,000   481,000   1,202,000
Total Assets 481,000   481,000   1,202,000
Contingent warrant liabilities 0   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]   0 [1]
U.S. treasury securities 0   0    
Foreign exchange option 0   0   0
Total Assets 0   0   0
Contingent warrant liabilities $ 32,179,000   $ 32,179,000   $ 379,000
[1] Included in cash and cash equivalents