Share-based compensation (Schedule Of Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Sharebased Compensation Schedule Of Stock Option Activity Legal Entity Details Abstract
Options, Outstanding as of beginning of period	5,104	4,646
Options, Granted	68	1,636
Options, Exercised	(693)	0
Options, Forfeited, or expired	(1,198)	(1,178)
Options, Outstanding as of end of period	3,281	5,104
Weighted-Average Exercise Prices, Outstanding as of beginnig of period	$ 1.66
Weighted-Average Exercise Prices, Granted	1.60	$ 0.65
Weighted-Average Exercise Prices, Exercised	1.44	0
Weighted-Average Exercise Prices, Forfeited, cancelled or expired	2.20	2.66
Weighted-Average Exercise Prices, Outstanding as of end of period	$ 1.51	$ 1.66
Options Outstanding, Weighted-Average Remaining Contractual Term (in years)	6 years 216 days	7 years 144 days
Options, Outstanding, Aggregate Intrinsic Value	$ 12,784	$ 122	$ 0
Options, Vested and expected to vest at end of period	3,193
Weighted-Average Exercise Price, Vested and expected to vest	$ 1.53
Weighted-Average Remaining Contractual Term (in years), Vested and expected to vest	6 years 180 days
Options, Vested and expected to vest, Aggregate Intrinsic Value	$ 12,379
Options, Exercisable at end of period	2,086
Weighted-Average Exercise Price, Exercisable	$ 1.86
Weighted-Average Remaining Contractual Term (in years), Exercisable	5 years 216 days
Options, Exercisable, Aggregate Intrinsic Value	$ 7,413
Grant date fair value of options vested	$ 604	$ 801