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Schedule II. Condensed Financial Information of Registrant (Parent Company) (Narrative) (Details) - USD ($) $ in Millions | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Parent Company |  |
Guarantor obligations, current carrying calue | $ 5 | $ 5
Guarantor obligations, maximum exposure, undiscounted | 1,800 |
Indemnification Agreement |  |
Guarantor obligations, maximum exposure, undiscounted | 252 |
Indemnification Agreement | Parent Company |  |
Guarantor obligations, maximum exposure, undiscounted | $ 625 |
CNAF Consolidated | Loews |  |
Noncontrolling interest, ownership percentage by parent | 89.00% |

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- Definition The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248 + Details
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- Definition Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248 + Details
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- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
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- Details
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