Policyholders' Liabilities - Liability for Future Policy Benefit, Discounted Undiscounted Activity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023
Life Insurance, Permanent
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	$ 731,580	$ 604,059
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	1,586,017	1,483,068
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	564,242	453,277
Expected future benefit payments	1,030,904	914,762
Life Insurance, Permanent Limited Pay
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	46,270	47,868
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	322,188	325,964
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	41,999	42,133
Expected future benefit payments	195,610	184,456
Home Service Insurance, Life Insurance, Permanent
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	448,837	459,405
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	487,851	484,239
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	272,938	261,271
Expected future benefit payments	212,887	193,584
Home Service Insurance, Life Insurance, Permanent Limited Pay
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	76,032	77,544
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	320,318	320,563
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	51,752	51,091
Expected future benefit payments	$ 120,606	$ 110,991