Summary of Significant Accounting Policies - Schedule of Potentially Dilutive Securities not Included in Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Shares Issuable upon Conversion of Series Seed Convertible
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included from calculation of diluted net loss per share		4,444,444
Shares Issuable upon Conversion of Series A Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included from calculation of diluted net loss per share		10,158,710
Shares Issuable upon Conversion of Series B Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included from calculation of diluted net loss per share		15,890,306
Shares Issuable upon Exercise of Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included from calculation of diluted net loss per share	8,099,861	2,104,311
Non-vested Shares under Restricted Stock Grants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities not included from calculation of diluted net loss per share	5,053,169	7,799,605