Share-Based Payments - 2021 Inducement Share Incentive Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 09, 2020
Fair Value Assumptions
Expected volatility (as a percent)			77.30%
Expected term of options (in years)			5 years 6 months
Risk-free interest rate (as a percent)			1.00%
Minimum
Fair Value Assumptions
Expected volatility (as a percent)			75.30%
Risk-free interest rate (as a percent)			1.02%
Maximum
Fair Value Assumptions
Expected volatility (as a percent)			76.30%
Risk-free interest rate (as a percent)			1.16%
Stock Options
Weighted average exercise price in $ per share
Share-based compensation expense	$ 100	$ 51	$ 200	$ 65
2021 Inducement Share Incentive Plan
Options
Granted (in shares)			129,250
Outstanding at end of year (in shares)	129,250		129,250
Weighted average exercise price in $ per share
Granted (in dollars per share)			$ 1.66
Outstanding balance at end of year (in dollars per share)	$ 1.66		$ 1.66
Fair Value Assumptions
Expected term of options (in years)			6 years 1 month 6 days
2021 Inducement Share Incentive Plan | Maximum
Share-Based Payments
Term of Awards			ten years
2021 Inducement Share Incentive Plan | Ordinary Shares
Share-Based Payments
Shares reserved for future issuance	70,750		70,750		200,000
2021 Inducement Share Incentive Plan | Stock Options
Weighted average exercise price in $ per share
Share-based compensation expense	$ 8		$ 8
Weighted-average grant date fair value (in dollars per share)			$ 1.09
Fair Value Assumptions
Weighted-average remaining contractual life			9 years 1 month 6 days
Unrecognized compensation expense
Total unrecognized compensation related to unvested options	$ 142		$ 142
Recognition period			4 years