Net Loss per Common Share (Antidilutive Shares Excluded from Computation of Diluted Shares Outstanding) (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	9,275,493	10,352,195	9,443,991	9,872,031
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	1,149,164	1,116,765	1,149,164	1,116,765
Warrant Liability [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	8,126,329	8,712,220	8,294,827	8,232,056
Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding		523,210		523,210