Stockholders' Equity - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Class Of Stock [Line Items]
Preferred stock, shares authorized	5,000,000
Preferred stock, par value | $ / shares	$ 0.0001
Preferred stock, shares outstanding	0
Preferred stock, shares issued	0
Conversion of stock, description	Each share of Class B common stock is convertible at any time at the option of the holder into one share of Class A common stock. In addition, each share of Class B common stock will convert automatically into one share of Class A common stock upon transfer, subject to certain exceptions, and upon the earlier of (1) the seventh anniversary of the closing of the IPO, and (2) the date on which the Class B common stock ceases to represent at least 25% of the outstanding common stock.
Class A Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	451,000,000
Common stock, par value | $ / shares	$ 0.0001
Common stock, shares issued	27,402,965
Common stock, shares outstanding	27,402,965
Common stock, entitled for voting rights	one vote per share
Number of shares issued for conversion	16,782,886
Class B Common Stock
Class Of Stock [Line Items]
Common stock, shares authorized	44,000,000
Common stock, par value | $ / shares	$ 0.0001
Common stock, shares issued	14,709,981
Common stock, shares outstanding	14,709,981
Common stock, entitled for voting rights	ten votes per share
Percentage of outstanding common stock, minimum	25.00%
Number of shares converted	16,782,886