Earnings Per Share (Reconciliation of Net Earnings to Net Earnings Attributable to Common Shares Used in Basic and Diluted Calculation) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Earnings from continuing operations	$ 43.5	$ 55.9	$ 115.8	$ 65.4
Earnings allocated to participating non-vested share awards	(0.2)	(0.2)	(0.4)	(0.2)
Earnings from continuing operations attributable to common shares	$ 43.3	$ 55.7	$ 115.4	$ 65.2