Common Stock Reserved For Issuance - Common Stock Reserved For Potential Future Issuances (Details) - shares	Jun. 30, 2018	Dec. 31, 2017
Class Of Stock [Line Items]
Total shares of common stock reserved	9,999,808	9,341,111
Shares Underlying Outstanding Stock Options
Class Of Stock [Line Items]
Total shares of common stock reserved	403,699	420,956
Shares Available For Future Stock Option Grants
Class Of Stock [Line Items]
Total shares of common stock reserved	35,591	19,034
Conversion of Outstanding Preferred Stock
Class Of Stock [Line Items]
Total shares of common stock reserved	7,039,155	7,039,155
Exchange of Vaccinex Products, LP Units
Class Of Stock [Line Items]
Total shares of common stock reserved	1,202,566	1,202,566
Conversion of VX3 Units
Class Of Stock [Line Items]
Total shares of common stock reserved	1,318,797	659,400