Common Stock - Additional Information (Details) - $ / shares	Jul. 02, 2018	Mar. 31, 2019	Dec. 31, 2018
Stockholders Deficit [Line Items]
Common stock, par value per share		$ 0.01	$ 0.01
Common stock, shares authorized for issuance		200,000,000	200,000,000
Common stock, shares issued		18,227,000	17,744,000
Common stock, shares outstanding		18,227,000	17,744,000
Initial Public Offering | Common Stock
Stockholders Deficit [Line Items]
Convertible preferred stock converted into common stock	11,000,000