Consolidated Statements of Changes in Equity (unaudited) - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2022	$ 4,228.7	$ 0.6	$ 1,637.8	$ 3,699.3	$ (986.2)	$ (122.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan exercises	7.4		7.4
Stock plan compensation expense	29.7		29.7
Common stock dividends	(76.7)			(76.7)
Acquisition of common stock	(36.5)		(21.2)	(15.3)
Net income	269.9			269.9
Other comprehensive (loss) income	63.5				63.5
Ending balance at Jun. 30, 2023	4,486.0	0.6	1,653.7	3,877.2	(922.7)	(122.8)
Beginning balance at Mar. 31, 2023	4,396.4	0.6	1,642.2	3,775.9	(899.5)	(122.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan compensation expense	17.2		17.2
Common stock dividends	(39.7)			(39.7)
Acquisition of common stock	(21.0)		(5.7)	(15.3)
Net income	156.3			156.3
Other comprehensive (loss) income	(23.2)				(23.2)
Ending balance at Jun. 30, 2023	4,486.0	0.6	1,653.7	3,877.2	(922.7)	(122.8)
Beginning balance at Dec. 31, 2023	4,809.5	0.6	1,668.5	4,028.2	(765.0)	(122.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan exercises	7.3		7.3
Stock plan compensation expense	34.6		34.6
Common stock dividends	(77.3)			(77.3)
Acquisition of common stock	(107.2)	(0.1)	(40.8)	(66.3)
Net income	425.1			425.1
Other comprehensive (loss) income	(87.7)				(87.7)
Ending balance at Jun. 30, 2024	5,004.3	0.5	1,669.6	4,309.7	(852.7)	(122.8)
Beginning balance at Mar. 31, 2024	4,920.0	0.6	1,659.2	4,194.2	(811.2)	(122.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock plan compensation expense	20.1		20.1
Common stock dividends	(39.9)			(39.9)
Acquisition of common stock	(43.1)	(0.1)	(9.7)	(33.3)
Net income	188.7			188.7
Other comprehensive (loss) income	(41.5)				(41.5)
Ending balance at Jun. 30, 2024	$ 5,004.3	$ 0.5	$ 1,669.6	$ 4,309.7	$ (852.7)	$ (122.8)