Earnings Per Share - Computation of Basic and Diluted Net EPS (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net earnings attributable to controlling interests	$ 62.3	$ 133.3	$ 139.3	$ 21.9	$ 51.5	$ 93.6	$ 109.0	$ 49.3	$ 356.8	$ 303.4	$ 268.6
Weighted average number of common shares outstanding									172.2	152.9	128.9
Dilutive effect of stock options using the treasury stock method									1.0	1.4	1.6
Weighted average number of common and common equivalent shares outstanding									173.2	154.3	130.5
Basic net earnings per share									$ 2.07	$ 1.98	$ 2.08
Diluted net earnings per share:									$ 2.06	$ 1.97	$ 2.06