Net Income (Loss) Per Share Attributable to Common Stockholders - Anti-dilutive effect (Details) - shares	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Antidilutive Securities
Antidilutive securities excluded from computation of diluted net loss per share		17,612,763
Option
Antidilutive Securities
Antidilutive securities excluded from computation of diluted net loss per share	3,000
Preferred Stock
Antidilutive Securities
Antidilutive securities excluded from computation of diluted net loss per share		15,560,569
Option to purchase common stock
Antidilutive Securities
Antidilutive securities excluded from computation of diluted net loss per share		2,052,194