Stockholders' Equity - Additional Information (Details)	9 Months Ended
	Sep. 30, 2017 $ / shares shares
Class Of Stock [Line Items]
Common stock shares authorized	75,000,000
Common stock par value | $ / shares	$ 0.0001
Common stock shares issued	16,365,738
Common stock shares outstanding	16,365,738
Common stock issued subject to repurchase related to early exercise of options	330,167
Convertible Preferred Stock
Class Of Stock [Line Items]
Preferred stock, conversion basis	one-for-one