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Largest Recoverables from Single Reinsurer

No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Amount of funds held as security for payments to be received under reinsurance contracts.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6811-158387

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Name:	us-gaap_CededCreditRiskAxis=cna_GatewayRiversInsuranceCompanyMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_CededCreditRiskAxis=cna_SubsidiariesofWiltonReMember
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