CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Total Shareholders’ Equity	Common Shares Issued at Par Value	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest
Balance, beginning of period at Dec. 31, 2017	$ 1,348.5	$ 1,345.2	$ 72.4	$ 291.7	$ 1,813.3	$ (380.1)	$ (452.1)	$ 3.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	335.5	335.6			335.6			(0.1)
Cash dividends	(83.5)	(83.5)			(83.5)
Reaquisition on open market	(50.1)	(50.1)					(50.1)
Exercise of stock options, net of shares reacquired	24.0	24.0					24.0
Stock-based compensation	21.6	21.6		21.6
Impact from settlement of share-based awards, net of shares acquired	(7.8)	(7.8)		(9.8)			2.0
Changes in pension and postretirement plan assets and benefit obligation, net of tax	(26.2)	(26.2)				(26.2)
Currency translation adjustment	(41.6)	(41.3)				(41.3)		(0.3)
Balance, end of period at Dec. 31, 2018	1,527.1	1,524.2	72.4	303.5	2,072.1	(447.6)	(476.2)	2.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative Effect of New Accounting Principle in Period of Adoption	6.7	6.7			6.7
Net income	133.6	133.3			133.3			0.3
Cash dividends	(93.2)	(93.2)			(93.2)
Reaquisition on open market	(79.9)	(79.9)					(79.9)
Exercise of stock options, net of shares reacquired	11.5	11.5					11.5
Stock-based compensation	22.3	22.3		22.3
Impact from settlement of share-based awards, net of shares acquired	(8.4)	(8.4)		(10.2)			1.8
Deconsolidation of a joint venture	(0.5)
Changes in pension and postretirement plan assets and benefit obligation, net of tax	(47.7)	(47.7)				(47.7)
Currency translation adjustment	11.5	11.6				11.6		(0.1)
Balance, end of period at Dec. 31, 2019	1,476.3	1,473.7	72.4	315.6	2,112.2	(483.7)	(542.8)	2.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	181.1	181.0			181.0			0.1
Cash dividends	(100.4)	(100.4)			(100.4)
Reaquisition on open market	(70.0)	(70.0)					(70.0)
Exercise of stock options, net of shares reacquired		8.9					8.9
Stock-based compensation	22.3	22.3		22.3
Impact from settlement of share-based awards, net of shares acquired	(3.9)	(3.9)		(7.2)			3.3
Changes in pension and postretirement plan assets and benefit obligation, net of tax	(53.6)	(53.6)				(53.6)
Currency translation adjustment	70.4	70.9				70.9		(0.5)
Balance, end of period at Dec. 31, 2020	$ 1,531.1	$ 1,528.9	$ 72.4	$ 330.7	$ 2,192.8	$ (466.4)	$ (600.6)	$ 2.2