Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Computation Of Earnings Per Share Line Items
Net income	$ 553.0	$ 358.6	$ 355.7
Net income from continuing operations	$ 556.0	$ 357.1	$ 361.7
Weighted average common shares outstanding
Basic (shares)	165.8	166.5	169.4
Dilutive impact of stock options and restricted stock awards (shares)	1.7	0.9	1.0
Diluted (shares)	167.5	167.4	170.4
Earnings (loss) per ordinary share
Continuing operations (USD per share)	$ 3.36	$ 2.14	$ 2.14
Discontinued operations (USD per share)	(0.02)	0.01	(0.04)
Basic earnings (loss) per common share (USD per share)	3.34	2.15	2.10
Continuing operations (USD per share)	3.32	2.13	2.12
Discontinued operations (USD per share)	(0.02)	0.01	(0.03)
Diluted earnings (loss) per common share (USD per share)	$ 3.30	$ 2.14	$ 2.09
Anti-dilutive stock options excluded from the calculation of diluted earnings per share	0.1	1.7	2.1