Stockholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended	6 Months Ended
	Oct. 22, 2018	Apr. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Class Of Stock [Line Items]
Proceeds from issuance of common stock in public offering, net				$ 46,308
Common stock, shares authorized			200,000,000	200,000,000	200,000,000
Common stock, par value			$ 0.001	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized			10,000,000	10,000,000	10,000,000
Preferred Stock, Par Value			$ 0.001	$ 0.001	$ 0.001
Common Stock
Class Of Stock [Line Items]
Common stock, shares, issued and sold			4,124,475
Initial Public Offering
Class Of Stock [Line Items]
Common stock, shares, issued and sold	9,864,666
Common stock, public offering price	$ 5.00
Proceeds from issuance of common stock in public offering, net	$ 43,000
Common stock, shares authorized			200,000,000	200,000,000
Common stock, par value			$ 0.001	$ 0.001
Preferred Stock, Shares Authorized			10,000,000	10,000,000
Preferred Stock, Par Value			$ 0.001	$ 0.001
Initial Public Offering | Common Stock
Class Of Stock [Line Items]
Redeemable convertible preferred stock converted to aggregate of common stock	13,200,115
Underwritten Public Offering
Class Of Stock [Line Items]
Common stock, shares, issued and sold		4,124,475
Common stock, public offering price		$ 12.00
Proceeds from issuance of common stock in public offering, net		$ 46,300