Income Taxes Income Taxes- Attributes Giving Rise to Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Deferred Tax Assets and Liabilities [Line Items]
Federal tax credit carryforwards	$ 294.7	$ 291.0
Pension liabilities	107.7	82.7
Deferred Tax Assets, Operating Loss Carryforwards	60.3	102.9
Liability for environmental remediation	47.0	29.3
Reserves and allowances	14.8	22.8
Deferred Tax Assets, Unrealized Currency Losses	12.1	12.8
Deferred Tax Assets Operating Lease Liabilities	8.1	0.0
Prepaid royalties	6.3	3.0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	5.4	6.5
Other	6.9	6.5
Total deferred tax assets	589.9	582.1
Intangible assets	(27.7)	(24.9)
Properties and equipment	(18.6)	(13.2)
Deferred Tax Liabilities Operating Lease Assets	(8.0)	0.0
Other	(1.4)	(5.6)
Total deferred tax liabilities	(55.7)	(43.7)
Deferred Tax Assets, Valuation Allowance	24.1	19.9
Net deferred tax assets	510.1	$ 518.5
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	4.2
State and Local Jurisdiction [Member]
Deferred Tax Assets and Liabilities [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	3.5
Domestic Tax Authority [Member]
Deferred Tax Assets and Liabilities [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	4.9
Foreign Tax Authority- Other Deferred Tax Assets [Member]
Deferred Tax Assets and Liabilities [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 5.8