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Variable Interest Entities (Narrative) (Detail) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2019 USD ($)
Variable Interest Entity [Line Items] |  |  |
Carrying amounts of assets | $ 6,632 |  | $ 7,284
Carrying amounts of liabilities | 6,135 |  | 6,445
Additional Voluntary Payment |  |  | 66
Variable Interest Entity Primary Beneficiary [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Carrying amounts of assets | 1,200 |  | 1,600
Carrying amounts of liabilities | $ 1,200 |  | $ 1,500
Variable Interest Entity Primary Beneficiary [Member] | U S Public Finance Insurance [Member] |  |  |
Variable Interest Entity [Line Items] |  |  |
Number of variable interest entities deconsolidated | 7 |  |
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 | 1 |  |

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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 Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(11)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599 Reference 3: 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(a)(12)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
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- Definition Sum of the carrying amounts as of the balance sheet date of all liabilities that are recognized. Liabilities are probable future sacrifices of economic benefits arising from present obligations of an entity to transfer assets or provide services to other entities in the future. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19-26) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118582676&loc=SL6759159-111685 + 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=118582676&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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