Net Loss Per Share Attributable to Common Stockholders - Weighted-Average Common Stock Equivalents Excluded from Calculation of Diluted Net Loss Per Share as They Had Anti-Dilutive Effect (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share		7,039,155		7,039,155
Employee Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	546,068	410,292	489,059	417,569
Vaccinex Products, LP Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	1,199,021	1,202,566	1,200,794	1,202,566
VX3 Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Weighted-average common stock equivalents excluded from calculation of diluted net loss per share	1,318,797	1,176,288	1,318,797	994,558