Risks and Liquidity (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended
	Nov. 30, 2019	Mar. 31, 2020	Dec. 31, 2019
Unusual Risk or Uncertainty [Line Items]
Accumulated deficit		$ (175,079)	$ (167,859)
Received net proceeds of after deducting underwriting discounts, commissions and other offering expenses	$ 50,600
IPO
Unusual Risk or Uncertainty [Line Items]
Number of shares issued and sold	4,398,700
Public offering price per share	$ 13.00
Over-Allotment Option
Unusual Risk or Uncertainty [Line Items]
Number of shares issued and sold	398,700