Statements of Changes in Consolidated Equity - USD ($) $ in Millions	Total	Cumulative effect of adoption of new accounting standard	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained Earnings Cumulative effect of adoption of new accounting standard	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Dec. 31, 2017	$ 1,844.5	$ 15.5	$ 12.7	$ 1,596.3	$ 1,184.3	$ 15.5	$ (26.1)	$ (1,027.8)	$ 105.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	236.7				222.4				14.3
Other comprehensive income (loss)	(112.2)							(106.0)	(6.2)
Dividends paid to noncontrolling interest	(10.0)								(10.0)
Sales of subsidiary shares to noncontrolling interest	2.7								2.7
Employee Stock Plans	14.4			19.1	(0.2)		(4.5)
Ending balance at Dec. 31, 2018	1,991.6		12.7	1,615.4	1,422.0		(30.6)	(1,133.8)	105.9
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	270.1				257.6				12.5
Other comprehensive income (loss)	(69.2)							(67.9)	(1.3)
Dividends paid to noncontrolling interest	(14.0)								(14.0)
Employee Stock Plans	14.7			2.6	(0.3)		12.4
Ending balance at Dec. 31, 2019	2,193.2		12.7	1,618.0	1,679.3		(18.2)	(1,201.7)	103.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,559.6)				(1,572.6)				13.0
Other comprehensive income (loss)	(10.5)							(21.9)	11.4
Equity component of convertible note	49.8			49.8
Convertible note capped call	(19.4)			(19.4)
Dividends paid to noncontrolling interest	(7.2)								(7.2)
Employee Stock Plans	(4.9)			(22.9)	(0.2)		18.2
Ending balance at Dec. 31, 2020	$ 641.4		$ 12.7	$ 1,625.5	$ 106.5		$ 0.0	$ (1,223.6)	$ 120.3