Loss per share -Schedule of EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	2 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Total net loss	$ (138.0)	$ (137.7)	$ (138.0)
Weighted average number of common shares (in shares)	22.2	23.5
Effect of dilutive securities:
Dilutive number of shares (in shares)	22.2	23.5
Basic loss per share (in dollars per share)		$ (5.86)	$ (6.22)
Diluted loss per share (in dollars per share)		$ (5.86)	$ (6.22)
Stock options
Effect of dilutive securities:
Effect of dilutive securities, Stock options and Restricted share units (in shares)	0.0	0.0
Restricted share units
Effect of dilutive securities:
Effect of dilutive securities, Stock options and Restricted share units (in shares)	0.0	0.0