Other assets - Schedule of Other Assets (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Non-current security deposits	$ 3.2	$ 5.0
Non-current insurance	0.1	2.8
Intangible assets, net	0.5	1.8
Other assets, net	$ 3.8	$ 9.6