Deferred Policy Acquisition Costs and Value of Business Acquired - VOBA Amortization Expense (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Insurance [Abstract]
2013	$ 113.1
2014	88.4
2015	80.7
2016	72.9
2017	$ 63.6

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Amount of amortization expense expected to be recognized during the next fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 20

-Section S99

-Paragraph 2

-Subparagraph (3)

-URI http://asc.fasb.org/extlink&oid=27015749&loc=d3e569990-122904

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- Definition

Amount of amortization expense expected to be recognized during the fifth fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

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- Definition

Amount of amortization expense expected to be recognized during the fourth fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

+ References

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- Definition

Amount of amortization expense expected to be recognized during the third fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

+ References

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- Definition

Amount of amortization expense expected to be recognized during the second fiscal year following the latest fiscal year for intangible assets arising from insurance contracts acquired in a business combination.

+ References

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