Derivative Financial Instruments (Fair Value Of The Company's Derivative Assets And Liabilities) (Details) - USD ($) $ in Millions		Sep. 30, 2015		Dec. 31, 2014
Derivative [Line Items]
Derivative Positions		$ (6.6)		$ (4.7)
Derivative Assets		4.7
Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative Notional Amount		252.9
S and P Five Hundred Index Options [Member] | Other Investments [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Assets	[1]	4.7		13.6
Derivative Liabilities		0.0	[1]	0.0
Derivative Notional Amount	[1]	451.1		418.2
Index Based Interest Guarantees [Member] | Other Policyholder Funds [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Assets	[2]	0.0		0.0
Derivative Liabilities	[2]	72.7		77.0
Derivative Notional Amount	[3]	0.0		0.0
Interest Rate Swaps [Member]
Derivative [Line Items]
Derivative Positions		(6.6)		(4.7)
Interest Rate Swaps [Member] | Other Liabilities [Member] | Designated As Hedging Instrument [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivative Assets	[1]	0.0		0.4
Derivative Liabilities	[1]	11.9		5.1
Derivative Notional Amount	[1]	350.0		350.0
Interest Rate Swaps [Member] | Other Liabilities [Member] | Designated As Hedging Instrument [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivative Assets	[1]	7.2		0.0
Derivative Liabilities	[1]	1.9		0.0
Derivative Notional Amount	[1]	$ 252.9		$ 0.0

[1] Reported in other invested assets and other liabilities.

[2] Reported in other policy holder funds.

[3] The underlying factors for index-based interest guarantees vary by contract and other criteria, such as floors and ceilings on rates and future payouts.