Fair Value Measurements (Reconciliation Of Changes In The Fair Value Of Liabilities) (Details) (Warrant Liabilities [Member], USD $)
9 Months Ended
Sep. 30, 2013
Sep. 30, 2012
Warrant Liabilities [Member]
   
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]    
Balance at January 1 $ 2,842,065 $ 868,725
Additions 1,406,441  
Unrealized gains (losses) 1,055,649 655,545
Unrealized gains on expiration (144)  
Transfers out of level 3 (1,111,795)  
Balance at June 30 $ 4,192,216 $ 1,524,270