Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Anti-dilutive securities
Potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive	13,300,094	11,679,486
Stock Options
Anti-dilutive securities
Potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive	13,240,089	11,582,818
Restricted Stock
Anti-dilutive securities
Potentially dilutive common shares that have not been included in the net loss per common share calculations because the effect would have been anti-dilutive	60,005	96,668