Shareholders' Equity - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		9 Months Ended
	May 08, 2020	May 10, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 31, 2019	Aug. 03, 2018
Equity, Class of Treasury Stock [Line Items]
Net earnings, net of tax, attributable to noncontrolling interests			$ 6.0	$ 12.2	$ 32.3	$ (46.1)
Dividend declared per share	$ 1.09	$ 1.09
Dividend declared date	May 08, 2020	May 10, 2019
Dividend payable date	Jun. 15, 2020	Jun. 14, 2019
Dividend record date	Jun. 01, 2020	Jun. 03, 2019
Shares authorized to be repurchased (in shares)							6,000,000.0	6,000,000.0
Shares repurchased during period (in shares)					900,000	1,800,000
Total cost of shares repurchased					$ 63.8	$ 152.0
August 2018 Authorization
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during period (in shares)					800,000
Shares remaining authorized for repurchase (in shares)			0		0
August 2019 Authorization
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during period (in shares)					100,000
Shares remaining authorized for repurchase (in shares)			5,900,000		5,900,000
Non-Controlling Interests
Equity, Class of Treasury Stock [Line Items]
Net earnings, net of tax, attributable to noncontrolling interests			$ 0.1	$ 0.2	$ (0.9)	$ 1.3