Location of and Gain (Loss) on Derivative Financial Instruments Not Designated as Hedging Instruments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Net Realized Investment Gain (Loss)
Credit Default Swap Loss	$ (0.4)	$ (0.3)
Gain on Embedded Derivative	8.5	6.4
Gains (Losses) on Derivatives Not Designated as Hedging Instruments	$ 8.1	$ 6.1

The amount of gain (loss) recognized in income relating to credit default swap derivatives

No definition available.

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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- Definition

Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

+ Details

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