Earnings Per Share (Reconciliation of Earnings to Earnings Attributable to Common Shares Used in Basic and Diluted Earnings (Loss) Per Share Calculation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Earnings Per Share [Abstract]
Net earnings	$ 308.7	$ 264.9	$ 223.8
(Earnings) allocated to participating vested share awards	0.0	0.0	(0.1)
(Earnings) allocated to participating vested share awards	0.0	0.0	(0.1)
Net earnings attributable to common shares, diluted	308.7	264.9	223.7
Net earnings attributable to common shares, basic	$ 308.7	$ 264.9	$ 223.7