Fair Value Measurements (Assets and Liabilities Measured at Fair Value on Recurring Basis) (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2013
Dec. 31, 2012
Liabilities    
Derivative liabilities on account of warrants $ 4,083 $ 7,612
Fair Value, Inputs, Level 1
   
Liabilities    
Derivative liabilities on account of warrants 0 0
Fair Value, Inputs, Level 2
   
Liabilities    
Derivative liabilities on account of warrants 0 0
Fair Value, Inputs, Level 3
   
Liabilities    
Derivative liabilities on account of warrants $ 4,083 $ 7,612