Earnings Per Share (Reconciliation of Earnings (Loss) to Earnings (Loss) Attributable to Common Shares Used in Basic and Diluted Earnings (Loss) Per Share Calculation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Earnings (loss) from continuing operations	$ 199.9	$ 185.3	$ (84.1)
(Earnings) allocated to participating vested share awards	(0.3)	(0.3)	(0.1)
Earnings (loss) from continuing operations attributable to common shares	$ 199.6	$ 185.0	$ (84.2)