Fair Value Measurements (Assets And Liabilities Measured On A Recurring Basis) (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative asset		$ 58.8	$ 1.4
Assets held for sale		50.2	2.2
Redeemable financial liability			174.8
Derivative liability		22.7	174.1
Liabilities held for sale		13.7	0.0
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Traded securities	[1]	26.2
Money market fund		2.4	0.0
Stable value fund	[2]	0.6	0.0
Available-for-sale Securities		37.5	27.9
Assets held for sale		50.2	2.2
Total assets		290.1	268.1
Liabilities held for sale		13.7
Total liabilities		462.8	585.5
Fair value, measurements, recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Traded securities	[1]	26.2
Available-for-sale Securities		37.5	27.9
Total assets		63.7	27.9
Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Money market fund		2.4
Assets held for sale		0.0	0.0
Total assets		175.6	238.0
Liabilities held for sale		0.0	0.0
Total liabilities		137.1	410.7
Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets held for sale		50.2	2.2
Total assets		50.2	2.2
Liabilities held for sale		13.7
Total liabilities		325.7	174.8
Redeemable financial liability | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Redeemable financial liability		312.0	174.8
Redeemable financial liability | Fair value, measurements, recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Redeemable financial liability		312.0	174.8
Call option | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative asset		62.2	180.1
Call option | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative asset		62.2	180.1
Foreign exchange contract | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative asset		111.0	57.9
Derivative liability		74.9	230.6
Foreign exchange contract | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative asset		111.0	57.9
Derivative liability		74.9	230.6
Embedded derivative financial instruments | Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability		62.2	180.1
Embedded derivative financial instruments | Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative liability		$ 62.2	$ 180.1

[1] Includes equity securities, fixed income and other investments measured at fair value.

[2] Certain investments that are measured at fair value using net asset value per share (or its equivalent) have not been classified in the fair value hierarchy.