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Fair Value Measurements - Information about Valuation Inputs for Variable Interest Entity Assets and Liabilities Classified as Level 3 (Detail) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31) |  |  |
Estimated Future Premium Payments Weighted Average Discounted Rate | 3.20% | 3.00% |
Asset-backed Securities [Member] |  |  |
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31) |  |  |
Fair Value Inputs Coupon Rate | 5.97% | 5.98% |
Fair Value Inputs Maturity | 12 years 9 months 18 days | 13 years 5 months 15 days |
Fair Value Inputs Yield | 12.00% | 12.60% |
Variable Interest Entity [Member] |  |  |
Fair Value Inputs, Liabilities, Quantitative Information [Line Items] (Deprecated 2018-01-31) |  |  |
Fair Value Asset Or Liability Measured On Recurring Basis Change In Unrealized Gains Losses Still Held |  |  | $ 235
Estimated Future Premium Payments Weighted Average Discounted Rate | 6.30% | 6.80% |
Estimated Future Premium Payments Minimum Discounted Rate | 5.30% | 5.80% |
Estimated Future Premium Payments Maximum Discounted Rate | 7.80% | 8.50% |

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- Definition Estimated Future Premium Payments Maximum Discounted Rate + References No definition available. + Details
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- Definition Estimated Future Premium Payments Minimum Discounted Rate + References No definition available. + Details
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- Definition Weighted average discounted rate of estimated future premium payments to be paid by the VIEs. + References No definition available. + Details
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- Definition The amount of gains or losses included in earnings attributable to unrealized gains or losses on financial instruments measured on a recurring basis using unobservable inputs that are still held at the reporting date. + References No definition available. + Details
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- Definition Fair value inputs coupon rate. + References No definition available. + Details
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- Definition Fair value inputs maturity. + References No definition available. + Details
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- Definition Fair value inputs yield. + 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 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 30 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-30 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 31 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-31 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 32 -Publisher FASB -URI https://asc.fasb.org//1943274/2147482907/825-10-50-32 + Details
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