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Earnings Per Share - Computation of Basic and Diluted Net EPS (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Net earnings attributable to controlling interests	$ 153.7	$ 110.1	$ 500.0	$ 444.2
Weighted average number of common shares outstanding	190.5	185.8	189.6	185.1
Dilutive effect of stock options using the treasury stock method	3.6	4.0	4.0	4.0
Weighted average number of common and common equivalent shares outstanding	194.1	189.8	193.6	189.1
Basic net earnings per share	$ 0.81	$ 0.59	$ 2.64	$ 2.40
Diluted net earnings per share	$ 0.79	$ 0.58	$ 2.58	$ 2.35

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