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Fair Value Measurement - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
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Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] |  |
Assets of consolidated investment vehicles (includes $99 and $331, at fair value) | $ 101 | $ 366
Other assets (includes $131 and $123, at fair value) | 746 | 706
Long-term debt | (1,699) | (1,694)
Other liabilities | (498) | (492)
Carrying Amount |  |
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] |  |
Assets of consolidated investment vehicles (includes $99 and $331, at fair value) | 0 | 19
Other assets (includes $131 and $123, at fair value) | 115 | 79
Financial guaranty insurance contracts | (2,029) | (2,244)
Long-term debt | (1,699) | (1,694)
Other liabilities | (16) | (15)
Estimated Fair Value |  |
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] |  |
Assets of consolidated investment vehicles (includes $99 and $331, at fair value) | 0 | 19
Other assets (includes $131 and $123, at fair value) | 116 | 80
Financial guaranty insurance contracts | (1,136) | (1,811)
Long-term debt | (1,579) | (1,593)
Other liabilities | $ (16) | $ (15)

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- Definition Assets of Consolidated Investment Vehicles + References No definition available. + Details
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- Definition This element represents the net financial guaranty contract position for the entity, consisting of premiums receivable, ceded unearned premium reserve, reinsurance recoverable on unpaid losses, salvage and subrogation recoverable, unearned premium reserve, loss and loss adjustment expense reserve, and reinsurance balances payable, net. + References No definition available. + Details
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- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-4 + Details
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