STATEMENTS OF CHANGES IN CONSOLIDATED EQUITY - USD ($) $ in Millions	Total	[CommonStockMember]	[AdditionalPaidInCapitalMember]	[RetainedEarningsMember]	[TreasuryStockMember]	[AccumulatedOtherComprehensiveIncomeMember]	[NoncontrollingInterestMember]
Total Stockholders' Equity 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	16.3			15.0			1.3
Other comprehensive income (loss)	43.5					38.3	5.2
Employee stock plans	(4.8)		(15.7)	0.0	10.9
Total Stockholders' Equity at Mar. 31, 2019	2,046.6	12.7	1,599.7	1,437.0	(19.7)	(1,095.5)	112.4
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	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