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, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share [Abstract]
Earnings from continuing operations	$ 223.8	$ 199.9	$ 185.3
(Earnings) allocated to participating vested share awards	(0.1)	(0.3)	(0.3)
(Earnings) allocated to participating vested share awards	(0.1)	(0.3)	(0.3)
Earnings from continuing operations attributable to common shares	$ 223.7	$ 199.6	$ 185.0