Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended
	Mar. 12, 2020	Apr. 12, 2019	Apr. 01, 2019	Apr. 02, 2018	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Apr. 30, 2019
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Conversion of convertible preferred stock into common stock upon initial public offering, Shares				24,168,656
Common Stock, capacity terminated								$ 17,600
Net loss					$ 35,331	$ 23,852
Accumulated deficit					235,005		$ 199,674
Initial Public Offering
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shares issued and sold				10,350,000
Common stock at a public offering price				$ 16.00
Net proceeds from initial public offering after underwriting discounts and commissions and offering expenses				$ 150,800
ATM
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Proceeds through future financings					$ 150,000
ATM | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shares issued and sold					0
ATM | Maximum
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Proceeds through future financings	$ 150,000		$ 100,000
Follow-On Offering | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shares issued and sold		5,555,556
Shares issued price per share		$ 22.50
Net proceeds after deducting underwriting discounts and commissions and offering expenses		$ 116,900
Underwriters Option | Common Stock
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Shares issued and sold		833,333
Shares issued price per share		$ 22.50
Net proceeds after deducting underwriting discounts and commissions and offering expenses		$ 17,600