Insurance Liabilities - Components of Contractholder Funds (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Liabilities for investment contracts:
Liabilities for individual annuities	$ 11,336.2	$ 10,864.9
GICs	9,969.1	10,290.7
Funding agreements	8,106.5	8,270.3
Other investment contracts	1,751.5	1,840.0
Total liabilities for investment contracts	31,163.3	31,265.9
Universal life and other reserves	6,919.2	6,687.7
Contractholder funds	$ 38,082.5	$ 37,953.6

Contractholder funds include reserves for investment contracts and reserves for universal life insurance.

No definition available.

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- Definition

Carrying amount of liabilities as of the balance sheet date pertaining to amounts received by the insurer for investment contracts not otherwise specified in the taxonomy.

+ References

No definition available.

+ Details

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- Definition

The amount of the liability as of the balance sheet date pertaining to amounts received by the insurer for funding agreements.

+ References

No definition available.

+ Details

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- Definition

The amount of the liability as of the balance sheet date pertaining to liabilities for individual annuities.

+ References

No definition available.

+ Details

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- Definition

The amount as of the balance sheet date pertaining to reserves for universal life and other reserves.

+ References

No definition available.

+ Details

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- Definition

Carrying amount of liabilities as of the balance sheet date pertaining to amounts received by the insurer or reinsurer from the insured (including a ceding company) under insurance or reinsurance contracts for which insurance risk is not transferred.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 30
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6387650&loc=d3e9420-108338

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- References

No definition available.

+ Details

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- Definition

The amount of the liability as of the balance sheet date pertaining to the guarantee given by the insurance entity to contract holders of a specified rate of return (a guaranteed yield) on their investments for a specified period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(14))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(13))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

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