Insurance - Schedule of Undiscounted and Discounted Expected Gross Premiums and Expected Future Benefits (Details) - USD ($) $ in Millions	Sep. 30, 2026	Sep. 30, 2025
Term and Whole Life
Expected future gross premiums:
Undiscounted	$ 290	$ 292
Discounted	206	224
Expected future benefit payments:
Undiscounted	404	449
Discounted	287	339
Accidental Death and Disability Protection
Expected future gross premiums:
Undiscounted	90	112
Discounted	63	82
Expected future benefit payments:
Undiscounted	114	140
Discounted	$ 76	$ 97

Liability For Future Policy Benefit, Expected Future Policy Benefit, Discounted, Before Reinsurance

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- References

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- Definition

Amount, before effect of reinsurance, of discounted balance for expected future gross premium component of liability for future policy benefit.

+ References

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- Definition

Amount, before effect of reinsurance, of undiscounted balance for expected future gross premium component of liability for future policy benefit.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-6

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 29E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-29E

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- Definition

Amount, before effect of reinsurance, of undiscounted balance for expected future policy benefit and expense component of liability for future policy benefit.

+ References

+ Details

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