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, 2020			52.9
Balance at the beginning of the period at Dec. 31, 2020		$ 2,537.7	$ 78.7	$ 441.7	$ (97.0)	$ 3,928.7	$ (1,814.4)
Balance at beginning (in shares) at Dec. 31, 2020							(25.5)
Increase (Decrease) in Shareholders' Equity
Net income		151.5				151.5
Other comprehensive income (loss), net of tax		(5.8)			(5.8)
Dividends		(56.0)				(56.0)
Repurchases of common stock (in shares)			1.6				1.6
Repurchases of common stock		(265.6)					$ (265.6)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		(0.6)				(0.6)
Issuances and deferrals. net for stock-based compensation	[1]	56.1		18.4			$ 37.7
Balance at ending (in shares) at Jun. 30, 2021			51.9
Balance at the end of the period at Jun. 30, 2021		2,417.9	$ 78.7	460.1	(102.8)	4,024.2	$ (2,042.3)
Balance at ending (in shares) at Jun. 30, 2021							(26.5)
Balance at beginning (in shares) at Mar. 31, 2021			52.1
Balance at the beginning of the period at Mar. 31, 2021		2,411.8	$ 78.7	443.4	(111.1)	3,952.4	$ (1,951.6)
Balance at beginning (in shares) at Mar. 31, 2021							(26.3)
Increase (Decrease) in Shareholders' Equity
Net income		99.3				99.3
Other comprehensive income (loss), net of tax		8.3			8.3
Dividends		(27.5)				(27.5)
Repurchases of common stock (in shares)			0.6				0.6
Repurchases of common stock		(115.6)					$ (115.6)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		(0.4)				(0.4)
Issuances and deferrals. net for stock-based compensation	[1]	41.6		16.7			$ 24.9
Balance at ending (in shares) at Jun. 30, 2021			51.9
Balance at the end of the period at Jun. 30, 2021		$ 2,417.9	$ 78.7	460.1	(102.8)	4,024.2	$ (2,042.3)
Balance at ending (in shares) at Jun. 30, 2021							(26.5)
Balance at beginning (in shares) at Dec. 31, 2021		52.0	52.0
Balance at the beginning of the period at Dec. 31, 2021		$ 2,629.5	$ 78.7	481.5	(105.2)	4,237.7	$ (2,063.2)
Balance at beginning (in shares) at Dec. 31, 2021		(26.4)					26.4
Increase (Decrease) in Shareholders' Equity
Net income		$ 495.1				495.1
Other comprehensive income (loss), net of tax		(37.0)			(37.0)
Dividends		(56.7)				(56.7)
Repurchases of common stock (in shares)			0.7				0.7
Repurchases of common stock		(175.0)					$ (175.0)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		(0.2)				(0.2)
Issuances and deferrals. net for stock-based compensation	[1]	$ 19.2		9.4			$ 9.8
Balance at ending (in shares) at Jun. 30, 2022		51.5	51.5
Balance at the end of the period at Jun. 30, 2022		$ 2,875.1	$ 78.7	490.9	(142.2)	4,676.1	$ (2,228.4)
Balance at ending (in shares) at Jun. 30, 2022		(26.9)					(26.9)
Balance at beginning (in shares) at Mar. 31, 2022			51.6
Balance at the beginning of the period at Mar. 31, 2022		$ 2,678.6	$ 78.7	483.5	(101.4)	4,402.6	$ (2,184.8)
Balance at beginning (in shares) at Mar. 31, 2022							26.8
Increase (Decrease) in Shareholders' Equity
Net income		301.5				301.5
Other comprehensive income (loss), net of tax		(40.8)			(40.8)
Dividends		(28.0)				(28.0)
Repurchases of common stock (in shares)			0.2				0.2
Repurchases of common stock		(50.0)					$ (50.0)
Issuances and deferrals, net for stock-based compensation (in shares)	[1]		(0.1)				(0.1)
Issuances and deferrals. net for stock-based compensation	[1]	$ 13.8		7.4			$ 6.4
Balance at ending (in shares) at Jun. 30, 2022		51.5	51.5
Balance at the end of the period at Jun. 30, 2022		$ 2,875.1	$ 78.7	$ 490.9	$ (142.2)	$ 4,676.1	$ (2,228.4)
Balance at ending (in shares) at Jun. 30, 2022		(26.9)					(26.9)

[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.