Net Income (Loss) per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	69,204,403	4,205,443	69,204,403	11,614,015
Redeemable convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	55,422,002	0	55,422,002	0
Options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	13,782,401	4,205,443	13,782,401	11,614,015