Changes In Equity And Accumulated Other Comprehensive Loss (Summary Of Changes In Equity) (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	$ 1,835.1	$ 1,531.1
Net income	105.0	108.4
Cash dividends	(26.4)	(25.0)
Reacquisition on open market	(175.8)
Impact from settlement of share-based awards, net of shares acquired	(5.4)	7.2
Stock-based compensation expense	5.9	6.3
Changes in pension and postretirement plan assets and benefit obligation, net of tax	3.3	4.9
Currency translation adjustment	(21.6)	(34.9)
Balance, end of period	$ 1,726.2	$ 1,598.0
Dividends per share (in dollars per share)	$ 0.47	$ 0.43
Treasury stock shares acquired	1,699,949
Exercise of stock options, net of shares reacquired	79,214
Common Shares Issued at Par Value
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	$ 72.4	$ 72.4
Balance, end of period	72.4	72.4
Capital Surplus
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	363.9	330.7
Impact from settlement of share-based awards, net of shares acquired	(5.1)	(2.3)
Stock-based compensation expense	5.9	6.3
Balance, end of period	364.7	334.7
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	2,527.3	2,192.8
Net income	105.0	108.4
Cash dividends	(26.4)	(25.0)
Balance, end of period	2,605.9	2,276.2
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(440.2)	(466.4)
Changes in pension and postretirement plan assets and benefit obligation, net of tax	3.3	4.9
Currency translation adjustment		(35.7)
Balance, end of period	(458.6)	(497.2)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(691.1)	(600.6)
Reacquisition on open market	(175.8)
Exercise of stock options, net of shares reacquired	6.1
Impact from settlement of share-based awards, net of shares acquired	(0.3)	9.5
Balance, end of period	(861.1)	(591.1)
Total Share- holders’ Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	1,832.3	1,528.9
Net income	105.0	108.4
Cash dividends	(26.4)	(25.0)
Reacquisition on open market	(175.8)
Exercise of stock options, net of shares reacquired	6.1
Impact from settlement of share-based awards, net of shares acquired	(5.4)	7.2
Stock-based compensation expense	5.9	6.3
Changes in pension and postretirement plan assets and benefit obligation, net of tax	3.3	4.9
Currency translation adjustment	(21.7)	(35.7)
Balance, end of period	1,723.3	1,595.0
Non-controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	2.8	2.2
Net income	0.0
Currency translation adjustment	0.1	0.8
Balance, end of period	$ 2.9	$ 3.0