CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock [Member]	Noncontrolling interests [Member]
Balance at Dec. 31, 2019	$ 2,053.5	$ 0.5	$ 1,353.7	$ 778.8	$ 19.9	$ (121.4)	$ 22.0
Balance, Shares at Dec. 31, 2019		47,291,463
Balance, Shares at Dec. 31, 2019						(1,541,675)
Purchase of treasury stock	(281.9)					$ (281.9)
Purchase of treasury stock, shares						(3,085,745)
Stock-based compensation expense	48.3		48.3
Vesting of restricted stock units and exercise of stock options	(1.9)		(38.1)			$ 36.2
Vesting of restricted stock units and exercise of stock options, shares						592,785
Dividends declared on common stock	(101.0)			(101.0)
Change in reporting entity resulting from common control transactions (Note 3)				0.9			(0.9)
Payments resulting from common control transactions (Note 3)	(2.1)			(2.1)
Contribution from a noncontrolling interest	0.8						0.8
Disposal of an entity	(1.4)		(1.4)
Change in pension and other postretirement benefit obligations, net of tax	14.6				14.6
Net income (loss)	808.1			811.5			(3.4)
Balance at Dec. 31, 2020	2,537.0	$ 0.5	1,362.5	1,488.1	34.5	$ (367.1)	18.5
Balance, Shares at Dec. 31, 2020		47,291,463
Balance, Shares at Dec. 31, 2020						(4,034,635)
Purchase of treasury stock	(536.8)					$ (536.8)
Purchase of treasury stock, shares						(3,575,568)
Stock-based compensation expense	46.7		46.7
Vesting of restricted stock units and exercise of stock options	(2.6)		(99.5)			$ 96.9
Vesting of restricted stock units and exercise of stock options, shares						1,076,169
Dividends declared on common stock	(118.2)			(118.2)
Change in reporting entity resulting from common control transactions (Note 3)	(6.4)		1.4	(0.2)			(7.6)
Contribution from a noncontrolling interest	0.3						0.3
Change in pension and other postretirement benefit obligations, net of tax	107.1				107.1
Net income (loss)	830.4			834.5			(4.1)
Balance at Dec. 31, 2021	$ 2,857.5	$ 0.5	1,311.1	2,204.2	141.6	$ (807.0)	7.1
Balance, Shares at Dec. 31, 2021	47,291,463	47,291,463
Balance, Shares at Dec. 31, 2021	(6,534,034)					(6,534,034)
Purchase of treasury stock	$ (880.7)					$ (880.7)
Purchase of treasury stock, shares						(5,055,304)
Stock-based compensation expense	61.6		61.6
Vesting of restricted stock units and exercise of stock options	(4.5)		(85.2)			$ 80.7
Vesting of restricted stock units and exercise of stock options, shares						1,116,701
Dividends declared on common stock	(142.2)			(142.2)
Noncontrolling interest from a business combination	24.9						24.9
Distribution to a noncontrolling interest	(6.5)						(6.5)
Contribution from a noncontrolling interest	30.4						30.4
Change in pension and other postretirement benefit obligations, net of tax	(114.4)				(114.4)
Other	$ (0.3)				(0.3)
Other, shares	(8,640)
Net income (loss)	$ 943.5			971.1			(27.6)
Balance at Dec. 31, 2022	$ 2,769.3	$ 0.5	$ 1,287.5	$ 3,033.1	$ 26.9	$ (1,607.0)	$ 28.3
Balance, Shares at Dec. 31, 2022	47,282,823	47,282,823
Balance, Shares at Dec. 31, 2022	(10,472,637)					(10,472,637)