STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY - USD ($) $ in Millions	Total	[CommonStockMember]	Additional Paid-in Capital [Member]	[RetainedEarningsMember]	[TreasuryStockMember]	[AccumulatedOtherComprehensiveIncomeMember]	[NoncontrollingInterestMember]
Total Stockholders' Equity 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)	23.6			21.1			2.5
Other comprehensive income (loss)	(15.7)					(14.9)	(0.8)
Employee stock plans	(8.5)		(25.9)	0.0	17.4
Total Stockholders' Equity at Mar. 31, 2020	2,192.6	12.7	1,592.1	1,700.4	(0.8)	(1,216.6)	104.8
Total Stockholders' Equity at Dec. 31, 2020	641.4	12.7	1,625.5	106.5	0.0	(1,223.6)	120.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(2.4)			(7.9)			5.5
Other comprehensive income (loss)	15.6					15.0	0.6
Employee stock plans	0.1		4.8	0.0	(4.7)
Total Stockholders' Equity at Mar. 31, 2021	$ 609.3	$ 12.7	$ 1,580.5	$ 103.0	$ (4.7)	$ (1,208.6)	$ 126.4