Share-Based Payments - 2019 Inducement Share Incentive Plan (Details) - 2019 Inducement Plan - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 12, 2019
Options
Outstanding at beginning of year (in shares)			605,650
Granted (in shares)			182,000
Forfeited (in shares)			(392,000)
Outstanding at end of year (in shares)	395,650		395,650
Vested and exercisable at end of year (in shares)	40,224		40,224
Weighted average exercise price in $ per share
Outstanding balance at beginning of year (in dollars per share)			$ 2.14
Granted (in dollars per share)			1.35
Forfeited (in dollars per share)			2.02
Outstanding balance at end of year (in dollars per share)	$ 1.96		1.96
Vested and exercisable balance at end of year (in dollars per share)	$ 2.64		$ 2.64
Share-based compensation expense	$ 0.1	$ 0.1	$ 0.1	$ 0.1
Unrecognized compensation expense
Total unrecognized compensation related to unvested options	$ 0.4		$ 0.4
Recognition period			1 year 6 months
Ordinary Shares
Share-Based Payments
Shares reserved for future issuance					2,000,000
Weighted average exercise price in $ per share
Weighted-average grant date fair value (in dollars per share)			$ 0.79
Stock Options
Share-Based Payments
Exercise period			10 years
Fair Value Assumptions
Expected volatility (as a percent)			59.80%
Expected term of options (in years)			6 years 1 month 6 days
Risk-free interest rate (as a percent)			2.90%
Weighted-average remaining contractual life			9 years 2 months 12 days
Stock Options | Minimum
Fair Value Assumptions
Expected volatility (as a percent)			63.70%
Risk-free interest rate (as a percent)			1.00%
Stock Options | Maximum
Fair Value Assumptions
Expected volatility (as a percent)			64.00%
Risk-free interest rate (as a percent)			1.40%
SARs
Share-Based Payments
Exercise period			10 years