Fair Value Of Assets And Liabilities (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016 USD ($) contract	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) on derivative	$ 2.5	$ 0.6
Number of futures contracts (as shown) | contract	2		15
Fair Value Inputs, Discount Rate	3.56%
Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate	0.69%
Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate	10.25%
Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets under Management, Assumed Growth Rate	4.13%
Future [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value of futures contracts	$ 0.3		$ 1.9
Designated as Hedging Instrument [Member] | Foreign Exchange Option [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Put option contracts, purchases	$ 7.0	$ 6.8