Net Loss per Common Share (Antidilutive Shares Excluded from Computation of Diluted Shares Outstanding) (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	27,344,397	9,420,075
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	863,892	1,116,043
Warrant Liability [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of diluted weighted shares outstanding	26,480,505	8,304,032