Derivative Financial Instruments (Effect Of Non-Hedging Derivatives On Income Statement And Included In Net Realized Gains (Losses) On Investments) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	$ (52.7)	$ (79.0)	$ (57.2)
Derivatives Embedded In Convertible Securities [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	31.5	(2.4)	(7.6)
Interest Rate Swaps [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	2.2
Credit Default And Interest Rate Swaps [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized		(3.9)	(53.3)
Options [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	(111.7)	(66.0)	9.6
Futures [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	22.3	(6.7)	(5.9)
Swaptions [Member] | Net Realized Gains (Losses) Investments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Gain (Loss) Recognized	$ 3.0