Fair Value Measurements (Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($) $ in Millions		Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset		$ 203.3	$ 28.9
Derivative liability		56.5	81.5
Liabilities Held For Sale, Current		0.0	9.3
Property, Plant, and Equipment, Fair Value Disclosure	[1]	$ 464.7	342.5	[2]
Weighted Average Discount Rate		15.00%
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, Plant, and Equipment, Fair Value Disclosure	[2]		104.0
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI		$ 65.6	54.8
Debt Securities, Held-to-maturity, Fair Value		24.2	71.9
Liabilities		47.3	25.8
Investments, Fair Value Disclosure		477.0	297.5
Liabilities Held For Sale, Current			9.3
Financial Liabilities Fair Value Disclosure		437.1	472.1
Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI		65.6	54.8
Debt Securities, Held-to-maturity, Fair Value			0.0
Investments, Fair Value Disclosure		65.6	54.8
Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity Securities, FV-NI			0.0
Debt Securities, Held-to-maturity, Fair Value		24.2	71.9
Investments, Fair Value Disclosure		363.2	214.8
Financial Liabilities Fair Value Disclosure		190.5	194.0
Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Securities, Held-to-maturity, Fair Value			0.0
Liabilities		47.3	25.8
Investments, Fair Value Disclosure		47.3	25.8
Liabilities Held For Sale, Current			9.3
Financial Liabilities Fair Value Disclosure		246.6	278.1
Synthetic bonds - embedded derivatives | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Synthetic bonds - embedded derivatives		246.6	268.8
Synthetic bonds - embedded derivatives | Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Synthetic bonds - embedded derivatives		246.6	268.8
Call option | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset			4.3
Call option | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset			4.3
Foreign exchange contract | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset		337.3	137.1
Derivative liability		190.5	189.7
Foreign exchange contract | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset		337.3	137.1
Derivative liability		190.5	189.7
Embedded derivative financial instruments | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability			4.3
Embedded derivative financial instruments | Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability		0.0
Embedded derivative financial instruments | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability			4.3
Nonqualified Plan | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund		1.7	1.5
Alternative Investment		0.9	2.1
Nonqualified Plan | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market fund		$ 1.7	$ 1.5

[1] Measured as of the impairment date using the income approach and a 10.8% risk-adjusted rate of interest, resulting in a Level 3 fair value measurement.

[2] Includes $104.0 million fair value of vessels determined using the transaction price of a similar vessel, resulting in a Level 2 fair value measurement.