Net Income (Loss) per Share Attributable to Common Stock - Summary of Anti-dilutive Stock Equivalents (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	68,720,341	59,539,641	68,720,341	12,679,454
Temporary equity outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	55,422,002	55,422,002	55,422,002	0
Options outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from earnings per share	13,298,339	4,117,639	13,298,339	12,679,454