Income Taxes - Income Tax Data from Continuing Operations (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income components:
United States	$ 143.9	$ 114.4	$ 89.2
International	270.5	276.6	220.2
Income from continuing operations before income tax	414.4	391.0	309.4
Current income tax expense:
United States – federal	9.4	6.3	7.7
United States – state and local	0.5	7.9	1.3
International	49.1	58.2	38.6
Total current income tax expense	59.0	72.4	47.6
Deferred income tax expense (benefit) components:
United States – federal	10.1	7.4	105.9
United States – state and local	1.5	(0.2)	4.4
International	19.3	(21.9)	36.7
Total deferred income tax expense (benefit)	30.9	(14.7)	147.0
Income tax expense	$ 89.9	$ 57.7	$ 194.6
Effective income tax rate	21.70%	14.80%	62.90%