Fair Value Measurements (Narrative) (Details) - Recurring [Member] - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents
Financial assets
Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents
Financial assets
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents
Financial assets
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents
Financial assets
Significant Unobservable Inputs (Level 3) [Member] | Warrants Issued May 2012 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant expiration date	May 01, 2018
Volatility rate	71.21%
Risk-free interest rate	1.31%
Closing stock price	$ 0.82
Significant Unobservable Inputs (Level 3) [Member] | Warrants Issued August 2013 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant expiration date	Nov. 01, 2018
Volatility rate	78.31%
Risk-free interest rate	1.31%
Closing stock price	$ 0.82
Significant Unobservable Inputs (Level 3) [Member] | Warrants Issued September 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant expiration date	Sep. 01, 2021
Volatility rate	92.83%
Risk-free interest rate	1.92%
Closing stock price	$ 0.82