Fair Value Measurements (Summary Of Changes In Fair Value Of Level 3 Financial Liabilities) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 19,574,977
Issues
Reclassifications	(16,984,616)
Settlements
Revaluation	(2,590,361)
Balance at end of period
Warrants Issued May 2012 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period
Issues
Reclassifications
Settlements
Revaluation
Balance at end of period
Warrants Issued August 2013 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	5,746
Issues
Reclassifications
Settlements
Revaluation	(5,746)
Balance at end of period
Warrants Issued September 2016 [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	19,569,231
Issues
Reclassifications	(16,984,616)
Settlements
Revaluation	(2,584,615)
Balance at end of period