Net Earnings Per Share (Reconciliation of Earnings (loss) to Earnings (loss) Attributable to Common Shares Used in Basic and Diluted (Loss) Earnings Per Share Calculation) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Earnings Per Share [Abstract]
Earnings from continuing operations	$ 69.5	$ 54.5	$ 177.0	$ 151.1
Earnings allocated to participating vested share awards	0.0	(0.1)	(0.1)	(0.2)
Earnings allocated to participating vested share awards	0.0	(0.1)	(0.1)	(0.2)
Earnings from continuing operations attributable to common shares	$ 69.5	$ 54.4	$ 176.9	$ 150.9