Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Additional Paid- In Capital	Retained Earnings	Accumulated Other Comprehensive Income (loss)	Non Controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	$ 0.6
Additional paid-in capital	892.8
Retained earnings	287.3
Accumulated other comprehensive loss, net	(72.7)
Noncontrolling interest	0.2
Beginning balance (in shares) at Dec. 31, 2019		61.4
Beginning balance at Dec. 31, 2019	1,108.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock compensation (in shares)		0.4
Employee stock compensation	59.4		$ 59.4
Deferred compensation	(2.6)		(3.8)	$ 1.2
Proceeds from stock issuances under employee plans (in shares)		0.5
Proceeds from stock issuances under employee plans	32.6		32.6
Cash dividends declared	(114.2)			(114.2)
Repurchase and retirement of common shares (in shares)		(0.6)
Repurchase and retirement of common shares	(49.5)		(8.2)	(41.3)
Net income (loss)	(73.9)			(74.0)		$ 0.1
Other comprehensive income (loss)	(12.2)				$ (12.2)
Ending balance (in shares) at Sep. 30, 2020		61.7
Ending balance at Sep. 30, 2020	947.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	0.6
Additional paid-in capital	921.3
Retained earnings	(69.3)
Accumulated other comprehensive loss, net	(99.6)
Noncontrolling interest	0.2
Beginning balance (in shares) at Jun. 30, 2020		61.3
Beginning balance at Jun. 30, 2020	753.2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock compensation	27.7		27.7
Deferred compensation	(2.0)		(1.9)	(0.1)
Proceeds from stock issuances under employee plans (in shares)		0.4
Proceeds from stock issuances under employee plans	25.7		25.7
Cash dividends declared	(38.2)			(38.2)
Repurchase and retirement of common shares	(0.2)		0.0	(0.2)
Net income (loss)	166.9			166.8		0.1
Other comprehensive income (loss)	14.7				14.7
Ending balance (in shares) at Sep. 30, 2020		61.7
Ending balance at Sep. 30, 2020	947.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	0.6
Additional paid-in capital	972.8
Retained earnings	59.0
Accumulated other comprehensive loss, net	(84.9)
Noncontrolling interest	0.3
Common stock	0.6
Additional paid-in capital	983.9
Retained earnings	218.4
Accumulated other comprehensive loss, net	(58.4)
Noncontrolling interest	0.3
Beginning balance (in shares) at Dec. 31, 2020		61.9
Beginning balance at Dec. 31, 2020	1,144.8
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock compensation (in shares)		0.4
Employee stock compensation	49.7		49.7
Deferred compensation	0.8		1.9	(1.1)
Proceeds from stock issuances under employee plans (in shares)		1.7
Proceeds from stock issuances under employee plans	151.7		151.7
Cash dividends declared	$ (115.2)			(115.2)
Repurchase and retirement of common shares (in shares)	(3.3)	(3.3)
Repurchase and retirement of common shares	$ (411.3)		(52.6)	(358.7)
Net income (loss)	407.5			407.1		0.4
Contributions	1.2					1.2
Other comprehensive income (loss)	(15.5)				(15.5)
Ending balance (in shares) at Sep. 30, 2021		60.7
Ending balance at Sep. 30, 2021	1,213.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	0.6
Additional paid-in capital	1,110.0
Retained earnings	73.5
Accumulated other comprehensive loss, net	(63.5)
Noncontrolling interest	1.7
Beginning balance (in shares) at Jun. 30, 2021		60.6
Beginning balance at Jun. 30, 2021	1,122.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee stock compensation (in shares)		0.1
Employee stock compensation	20.0		20.0
Deferred compensation	0.4		(1.0)	1.4
Proceeds from stock issuances under employee plans (in shares)		0.0
Proceeds from stock issuances under employee plans	5.6		5.6
Cash dividends declared	(38.2)			(38.2)
Repurchase and retirement of common shares (in shares)		0.0
Repurchase and retirement of common shares	(0.8)		$ 0.0	(0.8)
Net income (loss)	114.8			$ 114.6		$ 0.2
Other comprehensive income (loss)	(10.4)				$ (10.4)
Ending balance (in shares) at Sep. 30, 2021		60.7
Ending balance at Sep. 30, 2021	1,213.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	0.6
Additional paid-in capital	1,134.6
Retained earnings	150.5
Accumulated other comprehensive loss, net	(73.9)
Noncontrolling interest	$ 1.9