Derivative Financial Instruments - Fair Value of Derivatives (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Derivatives, fair value disclosures
Derivative instruments, assets	$ 194.0	$ 304.0
Derivative instruments, liabilities	291.7	688.1
Fair value of embedded derivative liabilities reported with contractholder funds	45.2	160.3
Derivatives designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	37.6	39.6
Derivative instruments, liabilities	29.6	59.2
Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	156.4	264.4
Derivative instruments, liabilities	262.1	628.9
Interest rate contracts \| Derivatives designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, liabilities	16.1	22.9
Interest rate contracts \| Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	108.0	175.2
Derivative instruments, liabilities	22.6	33.6
Foreign exchange contracts \| Derivatives designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	37.6	39.6
Derivative instruments, liabilities	13.5	36.3
Foreign exchange contracts \| Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	38.4	66.2
Derivative instruments, liabilities	72.9	26.3
Equity contracts \| Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	7.7	18.2
Derivative instruments, liabilities	27.6	154.1
Credit contracts \| Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, assets	2.3	4.8
Derivative instruments, liabilities	4.4	1.5
Other contracts \| Derivatives not designated as hedging instruments
Derivatives, fair value disclosures
Derivative instruments, liabilities	$ 134.6	$ 413.4

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://fasb.org/us-gaap/role/ref/legacyRef
-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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