Future Contract Benefit - Summary of Weighted-Average Interest Rates (Group Protection) (Details) - Group Protection	Sep. 30, 2024	Sep. 30, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Interest accretion rate	3.30%	3.00%
Current discount rate	4.40%	5.70%

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.

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Current weighted-average discount rate used to measure liability for future policy benefit.

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Original weighted-average discount rate at contract issue date used to measure liability for future policy benefit.

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