Organization and Description of Business (Details) $ / shares in Units, $ in Thousands			1 Months Ended		12 Months Ended
	Sep. 28, 2018 USD ($) $ / shares shares	Apr. 23, 2018	Mar. 31, 2016 shares	May 31, 2015 shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2019 USD ($) subsidiary
Number of subsidiaries | subsidiary						4
Shares issued (in shares)				4
Shares exchange ratio (as a percent)		100
Proceeds from initial public offering, net of issuance costs paid in the period | $					$ 66,071
Preferred stock including accrued dividends, converted into common stock	8,084,414
Going Concern
Cash, cash equivalents and short-term investments | $						$ 41,000
Initial Public Offering
Shares issued (in shares)	5,000,000
Share price (in dollars per share) | $ / shares	$ 15.00
Proceeds from initial public offering, net of issuance costs paid in the period | $	$ 65,600
Preferred stock including accrued dividends, converted into common stock	8,084,414
Series A Redeemable Convertible Preferred Stock
Shares issued (in shares)				33,499,900
Preferred stock including accrued dividends, converted into common stock					(33,499,900)
Series B Redeemable Convertible Preferred Stock
Shares issued (in shares)			25,000,000
Preferred stock including accrued dividends, converted into common stock					(25,000,000)