Condensed Consolidated Statements of Stockholders’ Equity (Unaudited) - USD ($) shares in Millions, $ in Millions		Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Shares in Treasury
Balance at beginning (in shares) at Dec. 31, 2022			50.9
Balance at the beginning of the period at Dec. 31, 2022		$ 3,024.4	$ 78.7	$ 512.6	$ (157.8)	$ 5,027.1	$ (2,436.2)
Balance at beginning (in shares) at Dec. 31, 2022							27.5
Increase (Decrease) in Shareholders' Equity
Net income		296.3				296.3
Other comprehensive income (loss), net of tax		14.3			14.3
Dividends		(77.3)				(77.3)
Repurchases of common stock (in shares)			(1.1)				1.1
Repurchases of common stock		(252.1)					$ (252.1)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		0.2				(0.2)
Issuances and deferrals. net for stock-based compensation	[1]	26.4		19.0			$ 7.4
Balance at ending (in shares) at Jun. 30, 2023			50.0
Balance at the end of the period at Jun. 30, 2023		3,032.0	$ 78.7	531.6	(143.5)	5,246.1	$ (2,680.9)
Balance at ending (in shares) at Jun. 30, 2023							28.4
Balance at beginning (in shares) at Mar. 31, 2023			50.8
Balance at the beginning of the period at Mar. 31, 2023		3,058.3	$ 78.7	516.0	(142.6)	5,089.8	$ (2,483.6)
Balance at beginning (in shares) at Mar. 31, 2023							27.6
Increase (Decrease) in Shareholders' Equity
Net income		194.6				194.6
Other comprehensive income (loss), net of tax		(0.9)			(0.9)
Dividends		(38.3)				(38.3)
Repurchases of common stock (in shares)			(0.9)				0.9
Repurchases of common stock		(201.9)					$ (201.9)
Issuances and deferrals, net for stock-based compensation (in shares)	[2]		0.1				(0.1)
Issuances and deferrals. net for stock-based compensation	[2]	20.2		15.6			$ 4.6
Balance at ending (in shares) at Jun. 30, 2023			50.0
Balance at the end of the period at Jun. 30, 2023		$ 3,032.0	$ 78.7	531.6	(143.5)	5,246.1	$ (2,680.9)
Balance at ending (in shares) at Jun. 30, 2023							28.4
Balance at beginning (in shares) at Dec. 31, 2023		47.7	47.7
Balance at the beginning of the period at Dec. 31, 2023		$ 2,829.0	$ 78.7	553.8	(111.1)	5,634.0	$ (3,326.4)
Balance at beginning (in shares) at Dec. 31, 2023		30.9					30.9
Increase (Decrease) in Shareholders' Equity
Net income		$ 904.7				904.7
Other comprehensive income (loss), net of tax		(1.9)			(1.9)
Dividends		(81.8)				(81.8)
Repurchases of common stock (in shares)			(1.8)				1.8
Repurchases of common stock		(705.5)					$ (705.5)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		0.5				(0.5)
Issuances and deferrals. net for stock-based compensation	[1]	$ 59.8		16.5			$ 43.3
Balance at ending (in shares) at Jun. 30, 2024		46.4	46.4
Balance at the end of the period at Jun. 30, 2024		$ 3,004.3	$ 78.7	570.3	(113.0)	6,456.9	$ (3,988.6)
Balance at ending (in shares) at Jun. 30, 2024		32.2					32.2
Balance at beginning (in shares) at Mar. 31, 2024			47.6
Balance at the beginning of the period at Mar. 31, 2024		$ 2,859.3	$ 78.7	562.8	(119.3)	5,784.8	$ (3,447.7)
Balance at beginning (in shares) at Mar. 31, 2024							31.0
Increase (Decrease) in Shareholders' Equity
Net income		712.4				712.4
Other comprehensive income (loss), net of tax		6.3			6.3
Dividends		(40.3)				(40.3)
Repurchases of common stock (in shares)			(1.3)				1.3
Repurchases of common stock		(555.0)					$ (555.0)
Issuances and deferrals, net for stock-based compensation (in shares)	[2]		0.1				(0.1)
Issuances and deferrals. net for stock-based compensation	[2]	$ 21.6		7.5			$ 14.1
Balance at ending (in shares) at Jun. 30, 2024		46.4	46.4
Balance at the end of the period at Jun. 30, 2024		$ 3,004.3	$ 78.7	$ 570.3	$ (113.0)	$ 6,456.9	$ (3,988.6)
Balance at ending (in shares) at Jun. 30, 2024		32.2					32.2

[1] Issuances and deferrals, net for stock-based compensation, reflects share activity related to option exercises, restricted and performance shares vested, and net issuances and deferrals associated with deferred compensation equity.

[2] Issuances and deferrals, net for stock-based compensation reflects share activity related to option exercises, restricted and performance shares vested, and net issuances and deferrals associated with deferred compensation equity.