Fair Value Measurements Equity Investments and Other Financial Instruments - Carrying Amounts and Estimated Fair Values of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Nov. 26, 2019
Senior Notes due December 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	4.875%
Senior Notes due April 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	5.25%
Senior Notes due September 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	4.50%
Senior Notes due December 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	5.125%
Senior Notes due September 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	5.50%
Senior Notes due December 2027
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	4.00%		4.00%
Senior Notes due July 2033
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Debt interest rate	6.875%
Carrying Amount
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other foreign loans	$ 8.8	$ 12.1
Other domestic borrowings	0.0	89.0
Total debt	3,726.7	3,774.4
Carrying Amount | Senior Notes due December 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	423.3	421.9
Carrying Amount | Senior Notes due April 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	422.9	422.0
Carrying Amount | Senior Notes due September 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	490.2	445.6
Carrying Amount | Senior Notes due December 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	422.1	421.9
Carrying Amount | Senior Notes due September 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	397.8	397.4
Carrying Amount | Senior Notes due December 2027
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	420.9	420.4
Carrying Amount | Senior Notes due July 2033
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	446.0	445.7
Carrying Amount | Term Loan A Facility due August 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	474.7	474.6
Carrying Amount | Term Loan A Facility Due July 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	220.0	223.8
Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other foreign loans	9.1	12.4
Other domestic borrowings	0.0	89.0
Total debt	4,099.6	4,073.9
Fair Value | Senior Notes due December 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	446.0	450.1
Fair Value | Senior Notes due April 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	450.8	454.1
Fair Value | Senior Notes due September 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	537.5	509.5
Fair Value | Senior Notes due December 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	466.8	458.9
Fair Value | Senior Notes due September 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	446.7	441.2
Fair Value | Senior Notes due December 2027
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	453.6	431.5
Fair Value | Senior Notes due July 2033
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	594.4	528.8
Fair Value | Term Loan A Facility due August 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	474.7	474.6
Fair Value | Term Loan A Facility Due July 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	$ 220.0	$ 223.8