Shareholders' Equity - Change in Shareholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	$ 2,335.4	$ 1,854.5
Net income	173.8	151.2
Activity related to stock-based compensation	$ 0.1	2.5
Share purchased under share repurchase program (in shares)	390,000
Shares purchased under share repurchase program	$ (147.1)	(137.1)
Dividends declared	(13.2)	(12.5)
Other comprehensive loss, net of tax	(22.8)	(29.6)
Balance, end of period	$ 2,326.2	$ 1,829.0
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance (in shares)	75,300,000	75,300,000
Balance, beginning of period	$ 18.8	$ 18.8
Balance (in shares)	75,300,000	75,300,000
Balance, end of period	$ 18.8	$ 18.8
Capital in Excess of Par Value
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	249.0	267.3
Activity related to stock-based compensation	(29.1)	(20.6)
Balance, end of period	$ 219.9	$ 246.7
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance (in shares)	1,100,000	1,300,000
Balance, beginning of period	$ (229.5)	$ (167.7)
Activity related to stock -based compensation (in shares)	(300,000)	(300,000)
Activity related to stock-based compensation	$ 29.2	$ 23.1
Share purchased under share repurchase program (in shares)	400,000	500,000
Shares purchased under share repurchase program	$ (147.1)	$ (137.1)
Balance (in shares)	1,200,000	1,500,000
Balance, end of period	$ (347.4)	$ (281.7)
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	2,456.7	1,846.7
Net income	173.8	151.2
Dividends declared	(13.2)	(12.5)
Balance, end of period	2,617.3	1,985.4
Accumulated other comprehensive loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of period	(159.6)	(110.6)
Other comprehensive loss, net of tax	(22.8)	(29.6)
Balance, end of period	$ (182.4)	$ (140.2)