Derivative Financial Instruments - Schedule of CDS Notional Amounts by Credit Rating And Fair Value of Protection Sold (Details) - Credit default contracts $ in Millions	Sep. 30, 2025 USD ($)
Derivative [Line Items]
Notional amount	$ 500
Fair value	12
AAA
Derivative [Line Items]
Notional amount	0
AA
Derivative [Line Items]
Notional amount	0
A
Derivative [Line Items]
Notional amount	0
BBB
Derivative [Line Items]
Notional amount	500
BB and lower
Derivative [Line Items]
Notional amount	$ 0

Fair value of credit risk derivative asset after deduction of credit risk derivative liability.

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-Topic 815
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-Name Accounting Standards Codification
-Section 50
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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/2009/role/commonPracticeRef
-Topic 815
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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
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