Derivative Financial Instruments - Fair Value of Derivaitves (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivatives, fair value disclosures
Derivative instruments, assets	$ 1,063.8	$ 666.6
Derivative instruments, liabilities	1,317.0	1,180.1
Fair value of embedded derivative liabilities reported with contractholder funds	213.0	177.4
Derivatives designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	111.3	103.5
Derivative instruments, liabilities	260.5	296.4
Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	952.5	563.1
Derivative instruments, liabilities	1,056.5	883.7
Interest rate contracts \| Derivatives designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	17.4	9.4
Derivative instruments, liabilities	139.1	132.2
Interest rate contracts \| Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	848.8	493.0
Derivative instruments, liabilities	446.6	255.8
Foreign exchange contracts \| Derivatives designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	93.9	94.1
Derivative instruments, liabilities	121.4	164.2
Foreign exchange contracts \| Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	25.5	16.4
Derivative instruments, liabilities	54.1	68.1
Equity contracts \| Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	62.7	39.8
Derivative instruments, liabilities	100.8	112.3
Credit contracts \| Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, assets	15.5	13.9
Derivative instruments, liabilities	28.8	39.7
Other contracts \| Derivatives not designated as hedging instrument
Derivatives, fair value disclosures
Derivative instruments, liabilities	$ 426.2	$ 407.8

This item represents the fair value of embedded derivatives that have been bifurcated from an investment host contract.

No definition available.

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- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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