Stockholders' Equity (Deficit) (Schedule of Stock-based Compensation) (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2015
Sep. 30, 2014
Sep. 30, 2015
Sep. 30, 2014
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock based compensation     $ 1,046,086 $ 722,358 $ 1,066,443 $ 571,924
Outstanding stock options [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock based compensation $ 245,289 $ 224,586 $ 942,136 $ 722,358 570,760 131,178
Non-employee stock options [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock based compensation         $ 495,683 415,212
Restricted stock awards [Member]            
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]            
Stock based compensation         $ 25,534