Income taxes, Components of Income Tax Credit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current [Abstract]
Current tax	$ (240)	$ (13,388)	$ (243)
Deferred [Abstract]
Deferred tax	5,843	1,728	93
Total income tax credit (expense)	5,603	(11,660)	(150)
United Kingdom [Member]
Current [Abstract]
Current tax	0	(12,420)	(54)
Deferred [Abstract]
Deferred tax	0	0	0
United States - Federal and State [Member]
Current [Abstract]
Current tax	215	(968)	(146)
Deferred [Abstract]
Deferred tax	5,873	1,694	93
Other Worldwide [Member]
Current [Abstract]
Current tax	(455)	0	(43)
Deferred [Abstract]
Deferred tax	$ (30)	$ 34	$ 0