Fair Value Measurements, Equity Investments and Other Financial Instruments - Carrying Amounts and Estimated Fair Values of Debt (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
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%
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 borrowings	$ 3.0	$ 8.8
Total debt	3,702.1	3,726.7
Carrying Amount | Senior Notes due December 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	423.7	423.3
Carrying Amount | Senior Notes due April 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	423.3	422.9
Carrying Amount | Senior Notes due September 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	474.4	490.2
Carrying Amount | Senior Notes due December 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	422.5	422.1
Carrying Amount | Senior Notes due September 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	398.0	397.8
Carrying Amount | Senior Notes due December 2027
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	421.1	420.9
Carrying Amount | Senior Notes due July 2033
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	446.1	446.0
Carrying Amount | Term Loan A due August 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	474.8	474.7
Carrying Amount | Term Loan A due July 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	215.2	220.0
Fair Value
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other foreign borrowings	3.0	9.1
Total debt	4,032.8	4,099.6
Fair Value | Senior Notes due December 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	442.5	446.0
Fair Value | Senior Notes due April 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	449.2	450.8
Fair Value | Senior Notes due September 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	514.0	537.5
Fair Value | Senior Notes due December 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	463.2	466.8
Fair Value | Senior Notes due September 2025
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	446.2	446.7
Fair Value | Senior Notes due December 2027
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	451.2	453.6
Fair Value | Senior Notes due July 2033
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Senior Notes	573.5	594.4
Fair Value | Term Loan A due August 2022
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	474.8	474.7
Fair Value | Term Loan A due July 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Term Loan A Facility	$ 215.2	$ 220.0