Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands		3 Months Ended
	Jan. 22, 2018	Mar. 31, 2019 USD ($) $ / shares	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($) $ / shares
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Date of incorporation		Mar. 13, 2014
Class A common stock, par value | $ / shares		$ 0.001		$ 0.001
Reverse stock split	1-for-5
Reverse stock split, conversion ratio	0.05
Cash		$ 18,656		$ 25,583
Operating loss		6,821	$ 4,717
Accumulated deficit		$ 93,668		$ 94,992