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Variable Interest Entities (Narrative) (Detail) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Mar. 31, 2019 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2018 USD ($) | Dec. 31, 2018 USD ($)
Variable Interest Entity [Line Items] |  |  |  |
Carrying amounts of assets |  | $ 2,300 |  | $ 1,700
Carrying amounts of liabilities |  | $ 2,300 |  | $ 1,700
Variable Interest Entity Primary Beneficiary [Member] | U S Public Finance Insurance [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Number of variable interest entities consolidated | 7 |  |  |
Net realized gains (losses) related to the initial consolidation | $ (42) |  |  |
Variable Interest Entity Primary Beneficiary [Member] | Structured Finance And International Insurance [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Number of variable interest entities deconsolidated |  | 2 |  |
Deconsolidation, Gain (Loss), Amount |  | $ (16) |  |
Variable Interest Entity Primary Beneficiary [Member] | Structured Finance And International Insurance [Member] | Zohar Funds Bankruptcy Cases Debtors [Member] |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |
Number of variable interest entities deconsolidated |  |  | 2 |
Deconsolidation, Gain (Loss), Amount |  |  | $ (93) |

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- Definition Represents the number of VIEs consolidated during the period. + References No definition available. + Details
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- Definition Represents the number of VIEs deconsolidated during the period. + References No definition available. + Details
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- Definition Amount of gain (loss) from deconsolidation of subsidiary and derecognition of group of assets constituting transfer of business or nonprofit activity, excluding conveyance of oil and gas mineral rights and transfer of good or service in contract with customer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684 + Details
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- Definition The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5710-111685 + Details
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- Definition The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (bb) -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5710-111685 + Details
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- Definition The gain (loss) recognized on initial consolidation of a variable interest entity (VIE) when the VIE is not a business (as defined). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=108788376&loc=d3e5710-111685 + Details
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- Definition 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. + References No definition available. + Details
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