Financial Guaranty Variable Interest Entities and Consolidated Investment Vehicles - Unpaid Principal (Details) - Variable Interest Entity, Primary Beneficiary - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Financial Guaranty Variable Interest Entities
Variable Interest Entity [Line Items]
FG VIEs’ liabilities with recourse	$ 34	$ 38
FG VIEs’ liabilities without recourse	16	16
Unpaid principal for FG VIEs’ liabilities with recourse	186	193
Financial Guaranty Variable Interest Entities
Variable Interest Entity [Line Items]
FG VIEs’ assets	259	264
Unpaid principal balance for FG VIEs’ assets that were 90 days or more past due	$ 23	$ 27

Fair Value, Option, Liabilities with Recourse, Unpaid Principal Balance

No definition available.

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- Definition

Fair Value, Option, Loans Held as Liabilities, Aggregate Difference, With Recourse

+ References

No definition available.

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- Definition

Fair Value, Option, Loans Held as Liabilities, Aggregate Difference, Without Recourse

+ References

No definition available.

+ Details

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- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of loans and long-term receivables (other than securities categorized as trading, available-for-sale or held-to-maturity) that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

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- Definition

This item represents the aggregate fair value of loans held as assets that are 90 days or more past due for which the fair value option has been elected.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

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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 810
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