Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments, Gain Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing			$ 2.1
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$ 0.2		0.2
Cumulative Foreign Currency Translation Gain Loss Recorded In Accumulated Other Comprehensive Income Loss For Terminated Net Investment In Foreign Operations Hedges	155.6		155.6		$ 75.8
Embedded Derivative Gain Loss In Financial Statements From Use Of Own Credit Risk	0.4	$ (0.5)	0.6	$ (1.8)
Embedded Derivative Gain Loss On Variable Annuity Contracts In Financial Statements From Use Of Own Credit Risk	$ 2.1	$ 1.0	$ 1.3	$ 1.6