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Derivative Instruments (Total Fair Value Of Company's Derivative Assets And Liabilities By Instrument And Balance Sheet Location, Before Counterparty Netting) (Detail) - Not Designated as Hedging Instrument [Member] - Derivative Instrument [Member] - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Derivative [Line Items] |  |
Derivative notional amount | $ 1,363 | $ 1,766
Derivative Assets, Not designated, Fair Value | 0 | 0
Derivative Liabilities, Not designated, Fair Value | (16) | (55)
Insured swaps [Member] |  |
Derivative [Line Items] |  |
Derivative notional amount | 1,269 | 1,350
Insured swaps [Member] | Other assets [Member] |  |
Derivative [Line Items] |  |
Derivative Assets, Not designated, Fair Value | 0 | 0
Insured swaps [Member] | Derivative liabilities [Member] |  |
Derivative [Line Items] |  |
Derivative Liabilities, Not designated, Fair Value | (1) | 0
Interest rate swaps [Member] |  |
Derivative [Line Items] |  |
Derivative notional amount | 55 | 380
Interest rate swaps [Member] | Other assets [Member] |  |
Derivative [Line Items] |  |
Derivative Assets, Not designated, Fair Value | 0 | 0
Interest rate swaps [Member] | Derivative liabilities [Member] |  |
Derivative [Line Items] |  |
Derivative Liabilities, Not designated, Fair Value | (1) | (49)
Currency swaps-VIE [Member] |  |
Derivative [Line Items] |  |
Derivative notional amount | 39 | 36
Currency swaps-VIE [Member] | Other assets-VIE [Member] |  |
Derivative [Line Items] |  |
Derivative Assets, Not designated, Fair Value | 0 | 0
Currency swaps-VIE [Member] | Derivative liabilities-VIE [Member] |  |
Derivative [Line Items] |  |
Derivative Liabilities, Not designated, Fair Value | $ (14) | $ (6)

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- Definition Fair value of derivative Asset Not Designated As Hedging Instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References No definition available. + Details
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- Definition Fair value of derivative liability Not Designated As Hedging Instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. + References No definition available. + 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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 815 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480237/815-40-50-5 + Details
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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
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