Shareholder's Equity - Change in Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance (in shares)			75,300,000				75,300,000
Beginning balance	$ 2,746.7	$ 2,776.2	$ 2,684.9	$ 2,424.4	$ 2,326.2	$ 2,335.4	$ 2,684.9	$ 2,335.4
Beginning balance (in shares)			1,200,000				1,200,000
Net income	161.3	155.1	$ 140.0	120.6	188.5	173.8	$ 456.4	$ 482.9
Activity related to stock-based compensation	$ 27.5	18.0	11.0	$ 15.6	15.1	0.1
Share purchased under share repurchase program (in shares)	77,329			86,667			753,399	563,334
Shares purchased under share repurchase program	$ (27.8)	(173.4)	(60.1)	$ (27.2)	(28.6)	(147.1)	$ (261.3)	$ (202.9)
Dividends declared		(14.1)	(14.2)		(13.3)	(13.2)
Other comprehensive income (loss), net of tax	$ (39.5)	(15.1)	14.6	(62.6)	(63.5)	(22.8)	$ (40.0)	(148.9)
Ending balance (in shares)	75,300,000						75,300,000
Ending balance	$ 2,868.2	$ 2,746.7	$ 2,776.2	$ 2,470.8	$ 2,424.4	$ 2,326.2	$ 2,868.2	$ 2,470.8
Ending balance (in shares)	1,300,000						1,300,000
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	75,300,000	75,300,000
Beginning balance	$ 18.8	$ 18.8	$ 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	75,300,000	75,300,000
Ending balance	$ 18.8	$ 18.8	$ 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	158.2	181.4	232.2	225.3	219.9	249.0	232.2	249.0
Activity related to stock-based compensation	(35.6)	(23.2)	(50.8)	5.3	5.4	(29.1)
Ending balance	122.6	158.2	181.4	230.6	225.3	219.9	122.6	230.6
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (501.4)	$ (369.2)	$ (370.9)	$ (366.3)	$ (347.4)	$ (229.5)	$ (370.9)	$ (229.5)
Beginning balance (in shares)	1,400,000	1,100,000	1,200,000	1,300,000	1,200,000	1,100,000	1,200,000	1,100,000
Activity related to stock-based compensation	$ 63.1	$ 41.2	$ 61.8	$ 10.3	$ 9.7	$ 29.2
Activity related to stock -based compensation (in shares)	(200,000)	(200,000)	(300,000)	(100,000)		(300,000)
Share purchased under share repurchase program (in shares)	100,000	500,000	200,000	100,000	100,000	400,000
Shares purchased under share repurchase program	$ (27.8)	$ (173.4)	$ (60.1)	$ (27.2)	$ (28.6)	$ (147.1)
Ending balance	$ (466.1)	$ (501.4)	$ (369.2)	$ (383.2)	$ (366.3)	$ (347.4)	$ (466.1)	$ (383.2)
Ending balance (in shares)	1,300,000	1,400,000	1,100,000	1,300,000	1,300,000	1,200,000	1,300,000	1,300,000
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 3,254.6	$ 3,113.6	$ 2,987.8	$ 2,792.5	$ 2,617.3	$ 2,456.7	$ 2,987.8	$ 2,456.7
Net income	161.3	155.1	140.0	120.6	188.5	173.8
Dividends declared		(14.1)	(14.2)		(13.3)	(13.2)
Ending balance	3,415.9	3,254.6	3,113.6	2,913.1	2,792.5	2,617.3	3,415.9	2,913.1
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(183.5)	(168.4)	(183.0)	(245.9)	(182.4)	(159.6)	(183.0)	(159.6)
Other comprehensive income (loss), net of tax	(39.5)	(15.1)	14.6	(62.6)	(63.5)	(22.8)
Ending balance	$ (223.0)	$ (183.5)	$ (168.4)	$ (308.5)	$ (245.9)	$ (182.4)	$ (223.0)	$ (308.5)