Common Stock - Additional Information (Details)	12 Months Ended
	Dec. 31, 2017 USD ($) Vote Class $ / shares shares	Dec. 31, 2016 $ / shares shares	Apr. 12, 2016 $ / shares shares
Class Of Stock [Line Items]
Stock split ratio	0.095
shares authorized | shares			510,000,000
Common stock, shares authorized | shares	500,000,000	500,000,000	500,000,000
Preferred stock, shares authorized | shares	10,000,000	10,000,000	10,000,000
Common stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Preferred stock, par value	$ 0.0001	$ 0.0001	$ 0.0001
Number of common stock holders voting right | Vote	1
Common stock voting rights	Each holder of common stock is entitled to one vote for each share of common stock held.
Common stock dividends declared | $	$ 0
Number of classes of common shares authorized | Class	3
Common stock conversion ratio	100.00%
Common stock conversion basis	each outstanding Common A-1 and Common A share was automatically converted into one share of common stock, par value $0.0001 per share
Class A-1 Common
Class Of Stock [Line Items]
Common stock, par value	$ 0
Class A Common
Class Of Stock [Line Items]
Common stock, par value	0
Class B Common
Class Of Stock [Line Items]
Common stock, par value	$ 0