Nature of Business and Basis of Presentation - Additional Information (Details) $ / shares in Units, $ in Millions			9 Months Ended
	Apr. 02, 2018 USD ($) $ / shares shares	Mar. 16, 2018	Sep. 30, 2018 shares	May 14, 2018 shares	Dec. 31, 2017 shares
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Reverse stock split ratio of issued and outstanding shares of common stock			one-for-5.263
Reverse stock split ratio of issued and outstanding shares of common stock, conversion		5.263
Reverse stock split effective date			Mar. 16, 2018
Convertible preferred shares converted to common stock	24,168,656
Preferred stock outstanding			0		0
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 | $ / shares	$ 16.00
Proceeds from issuance of common stock | $	$ 165.6
Convertible preferred shares converted to common stock	24,168,656
Preferred stock outstanding				0