Shareholder's Equity - Change in Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)		75,300,000			75,300,000
Beginning balance	$ 2,326.2	$ 2,335.4	$ 1,829.0	$ 1,854.5	$ 2,335.4	$ 1,854.5
Net income	188.5	173.8	187.3	151.2	$ 362.3	338.5
Activity related to stock-based compensation	$ 15.1	0.1	21.8	2.5
Share purchased under share repurchase program (in shares)	86,667				476,667
Shares purchased under share repurchase program	$ (28.6)	(147.1)		(137.1)	$ (175.7)
Dividends declared	(13.3)	(13.2)	(12.5)	(12.5)
Other comprehensive (loss) income, net of tax	$ (63.5)	(22.8)	7.0	(29.6)	$ (86.3)	(22.6)
Ending balance (in shares)	75,300,000				75,300,000
Ending balance	$ 2,424.4	$ 2,326.2	$ 2,032.6	$ 1,829.0	$ 2,424.4	$ 2,032.6
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)	75,300,000	75,300,000	75,300,000	75,300,000	75,300,000	75,300,000
Beginning balance	$ 18.8	$ 18.8	$ 18.8	$ 18.8	$ 18.8	$ 18.8
Ending balance (in shares)	75,300,000	75,300,000	75,300,000	75,300,000	75,300,000	75,300,000
Ending balance	$ 18.8	$ 18.8	$ 18.8	$ 18.8	$ 18.8	$ 18.8
Capital in Excess of Par Value
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	219.9	249.0	246.7	267.3	249.0	267.3
Activity related to stock-based compensation	5.4	(29.1)	1.3	(20.6)
Ending balance	225.3	219.9	248.0	246.7	225.3	248.0
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (347.4)	$ (229.5)	$ (281.7)	$ (167.7)	$ (229.5)	$ (167.7)
Beginning balance (in shares)	1,200,000	1,100,000	1,500,000	1,300,000	1,100,000	1,300,000
Activity related to stock -based compensation (in shares)		(300,000)	(200,000)	(300,000)
Activity related to stock-based compensation	$ 9.7	$ 29.2	$ 20.5	$ 23.1
Share purchased under share repurchase program (in shares)	100,000	400,000		500,000
Shares purchased under share repurchase program	$ (28.6)	$ (147.1)		$ (137.1)
Ending balance	$ (366.3)	$ (347.4)	$ (261.2)	$ (281.7)	$ (366.3)	$ (261.2)
Ending balance (in shares)	1,300,000	1,200,000	1,300,000	1,500,000	1,300,000	1,300,000
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 2,617.3	$ 2,456.7	$ 1,985.4	$ 1,846.7	$ 2,456.7	$ 1,846.7
Net income	188.5	173.8	187.3	151.2
Dividends declared	(13.3)	(13.2)	(12.5)	(12.5)
Ending balance	2,792.5	2,617.3	2,160.2	1,985.4	2,792.5	2,160.2
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(182.4)	(159.6)	(140.2)	(110.6)	(159.6)	(110.6)
Other comprehensive (loss) income, net of tax	(63.5)	(22.8)	7.0	(29.6)
Ending balance	$ (245.9)	$ (182.4)	$ (133.2)	$ (140.2)	$ (245.9)	$ (133.2)