Fair Value Of Assets And Liabilities (Narrative) (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign time deposits			$ 28.6
Equity Method Investments	$ 308.7	$ 308.7	277.3
Other Investments	5.8	5.8	6.2
Derivative, Notional Amount	172.5	172.5
Derivative, Loss on Derivative	(1.3)
Derivative Liability	(1.3)	$ (1.3)
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate		2.34%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate		(0.74%)
Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate		(0.03%)
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign time deposits	20.1	$ 20.1	28.6
Fair Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign time deposits	$ 20.1	$ 20.1	$ 28.6
Discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Inputs, Discount Rate (Deprecated 2018-01-31)	0.0484	0.0484