Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Embedded Derivative, Fair Value of Embedded Derivative, Net	$ 5,041.0	$ 5,205.0
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months	$ 5.0
Maximum Length of Time Hedged in Cash Flow Hedge	19 years
Credit Derivative, Maximum Exposure, Undiscounted	$ 3.0	7.0
Credit Risk Derivatives, at Fair Value, Net Asset (Liability) (less than)	(0.3)	0.0
Policyholders' Account Balances
Embedded Derivative, Fair Value of Embedded Derivative, Net	20.0	6.0
Future Policy Benefits
Embedded Derivative, Fair Value of Embedded Derivative, Net	5,041.0	5,205.0
Reinsurance Recoverables
Embedded Derivative, Fair Value of Embedded Derivative, Net	(5,474.0)	(4,940.0)
Union Hamilton Reinsurance, Ltd. \| Reinsurance Recoverables
Embedded Derivative, Fair Value of Embedded Derivative, Net	0.0	(7.0)
UPARC \| Reinsurance Recoverables
Embedded Derivative, Fair Value of Embedded Derivative, Net	(433.0)	(340.0)
PALAC and Prudential Insurance \| Reinsurance Recoverables
Embedded Derivative, Fair Value of Embedded Derivative, Net	$ (5,041.0)	$ (4,593.0)

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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- Definition

Maximum potential amount of future undiscounted payments that could be required under the credit derivative, before reduction for potential recoveries under recourse or collateralization provisions.

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- Definition

Fair value of credit risk derivative asset after deduction of credit risk derivative liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4K
-Subparagraph (c)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 15
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- Definition

Net fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as assets, net of those classified as liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
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-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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- Definition

Maximum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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-Name Accounting Standards Codification
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-SubTopic 30
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