Policyholders' Liabilities - Liability for Future Policy Benefit, Discounted Undiscounted Activity (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2020
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Policy Benefit, before Reinsurance, after Discount Rate Change			$ 1,613,279
Life Insurance, Permanent
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	$ 604,059	$ 614,123
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	1,483,068	1,471,197
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	453,277	471,719
Liability for Future Policy Benefit, Expected Future Policy Benefit, before Reinsurance, after Discount Rate Change	914,762	934,111
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	47,868	48,132
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	325,964	322,184
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	42,133	42,441
Liability for Future Policy Benefit, Expected Future Policy Benefit, before Reinsurance, after Discount Rate Change	184,456	193,898
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	459,405	465,752
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	484,239	472,958
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	261,271	272,158
Liability for Future Policy Benefit, Expected Future Policy Benefit, before Reinsurance, after Discount Rate Change	193,584	200,408
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	77,544	74,126
Liability for Future Policy Benefit, Expected Future Policy Benefit, Undiscounted, before Reinsurance	320,563	316,178
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	51,091	52,036
Liability for Future Policy Benefit, Expected Future Policy Benefit, before Reinsurance, after Discount Rate Change	$ 110,991	$ 117,159