Aggregate Limit

No definition available.

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- Definition

Benefit Recognized Under Retroactive Reinsurance Accounting

+ References

No definition available.

+ Details

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- Definition

Benefit Unrecognized Under Retroactive Reinsurance Accounting

+ References

No definition available.

+ Details

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- Definition

Catastrophe Losses Net Of Reinsurance

+ References

No definition available.

+ Details

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- Definition

Claim and allocated claim adjustment expense reserves under existing third party reinsurance contracts.

+ References

No definition available.

+ Details

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- Definition

Total consideration paid to NICO.

+ References

No definition available.

+ Details

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- Definition

Cumulative Amounts Ceded Under Loss Portfolio Transfer

+ References

No definition available.

+ Details

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- Definition

Deferred retroactive reinsurance gain.

+ References

No definition available.

+ Details

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- Definition

Fair Value Of Collateral Trust Account

+ References

No definition available.

+ Details

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- Definition

Favorable Net Prior Year Development

+ References

No definition available.

+ Details

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- Definition

Net Prior Year Claim and Allocated Claim Adjustment, Workers Compensation

+ References

No definition available.

+ Details

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- Definition

Percentage of premium and losses related to reinsurance.

+ References

No definition available.

+ Details

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- Definition

Percentage of third party capital provider.

+ References

No definition available.

+ Details

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- Definition

Reinsurance Premium

+ References

No definition available.

+ Details

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- Definition

Reinsurance Receivables Net Book Value

+ References

No definition available.

+ Details

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- Details

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- Definition

Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos and environmental claims, net of estimated reinsurance recoveries.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

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Claim and Claim Adjustment Expense Reserves - Additional Information (Detail) (USD $)	12 Months Ended			3 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2010
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses, net of reinsurance	$ 156,000,000l_CatastropheLossesNetOfReinsurance	$ 169,000,000l_CatastropheLossesNetOfReinsurance	$ 391,000,000l_CatastropheLossesNetOfReinsurance
Deferred retroactive reinsurance benefit recognized	13,000,000	314,000,000	261,000,000	314,000,000
Fair value of the collateral trust account	3,400,000,000l_FairValueOfCollateralTrustAccount
Commercial [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Favorable development in accident years	139,000,000	91,000,000	15,000,000
Commercial [Member] \| 1996 and Prior [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Favorable development in accident years	26,000,000
International [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Commutation of third party capital provider, percentage		15.00%
Percentage of premium, losses and expenses		15.00%
A&EP Reserves [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Net A&EP claim and allocated claim adjustment expense reserves					1,600,000,000
Aggregate limit under A&EP Loss Portfolio Transfer					4,000,000,000
Ceded A&EP claim and allocated claim adjustment expense reserves					1,200,000,000
Reinsurance premium paid to NICO under A&EP Loss Portfolio Transfer					2,000,000,000
Net reinsurance receivables transferred to NICO under A&EP Loss Portfolio Transfer					215,000,000
Total consideration				2,200,000,000	2,200,000,000
Net ultimate losses ceded under the Loss Portfolio Transfer				189,000,000
Cumulative amounts ceded under the Loss Portfolio Transfer		2,500,000,000		2,500,000,000
Deferred retroactive reinsurance benefit recognized	13,000,000
Remaining unrecognized benefit	176,000,000
Life & Group Non-Core [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Favorable net prior year development	$ 14,000,000	$ 9,000,000	$ 11,000,000