Stockholders' Equity (Schedule of Common Stock Reserved for Future Issuance) (Details)	Dec. 31, 2018 shares
Class of Stock [Line Items]
Common Stock Reserved for Future Issuance	7,806,839
Exercise Of Stock Options [Member]
Class of Stock [Line Items]
Common Stock Reserved for Future Issuance	5,757,305
Exercise Of Warrants [Member]
Class of Stock [Line Items]
Common Stock Reserved for Future Issuance	2,049,534