Net Earnings Per Share - Calculations of Net Earnings Per Share - Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net earnings available to common shareholders	$ (13.3)	$ 145.1	$ 88.8
Weighted-average common shares outstanding (in millions):
Weighted-average common shares outstanding - basic	46.6	47.8	49.8
Weighted average shares - diluted	46.6	48.3	50.4
Net (loss) earnings per share - basic	$ (0.29)	$ 3.04	$ 1.78
Net (loss) earnings per share - diluted	$ (0.29)	$ 3.01	$ 1.76
Effect of other share-based awards
Weighted-average common shares outstanding (in millions):
Effect of dilutive securities	0.0	0.5	0.6