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Schedule IV - (Reinsurance) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Direct Amount	$ 4	$ 5	$ (3)
Ceded to Others	0	0	0
Assumed from Other Companies	0	0	0
Net Amount	$ 4	$ 5	$ (3)
Percentage of Amount Assumed to Net	0.00%	0.00%	0.00%

X

- Definition

Direct amount premiums written.

+ References

No definition available.

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X

- Definition

Premiums written financial guarantee insurance contracts percentage of amount assumed to net.

+ References

No definition available.

+ Details

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X

- References

No definition available.

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X

- Definition

Amount of written premiums assumed from other entities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

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Balance Type:	credit
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X

- Definition

Amount of written premiums ceded to other entities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 944
-SubTopic 605
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

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Balance Type:	debit
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X

- Definition

Amount, after premiums ceded to other entities and premiums assumed by the entity, of premiums written.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-SubTopic 605
-Topic 944
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-SubTopic 605
-Topic 944
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479032/944-605-50-1

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