Policyholders' Liabilities - Liabilities for Future Policy Benefits, Weighted Average (Details)	Mar. 31, 2024	Mar. 31, 2023
Life Insurance, Permanent
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Weighted-Average Duration, Original Discount	8 years 2 months 12 days	8 years 1 month 6 days
Liability for Future Policy Benefit, Weighted-Average Duration	8 years 6 months	8 years 4 months 24 days
Liability for Future Policy Benefit, Original Weighted-Average Discount Rate	4.89%	4.92%
Liability for Future Policy Benefit, Current Weighted-Average Discount Rate	5.10%	4.86%
Life Insurance, Permanent Limited Pay
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Weighted-Average Duration, Original Discount	8 years 1 month 6 days	7 years 7 months 6 days
Liability for Future Policy Benefit, Weighted-Average Duration	7 years 9 months 18 days	7 years 7 months 6 days
Liability for Future Policy Benefit, Original Weighted-Average Discount Rate	4.28%	4.30%
Liability for Future Policy Benefit, Current Weighted-Average Discount Rate	5.09%	4.85%
Home Service Insurance, Life Insurance, Permanent
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Weighted-Average Duration, Original Discount	16 years	15 years 10 months 24 days
Liability for Future Policy Benefit, Weighted-Average Duration	15 years 9 months 18 days	16 years 1 month 6 days
Liability for Future Policy Benefit, Original Weighted-Average Discount Rate	4.97%	4.99%
Liability for Future Policy Benefit, Current Weighted-Average Discount Rate	5.31%	5.09%
Home Service Insurance, Life Insurance, Permanent Limited Pay
Liability for Future Policy Benefit, Activity [Line Items]
Liability for Future Policy Benefit, Weighted-Average Duration, Original Discount	14 years 6 months	14 years 6 months
Liability for Future Policy Benefit, Weighted-Average Duration	14 years 6 months	15 years 2 months 12 days
Liability for Future Policy Benefit, Original Weighted-Average Discount Rate	5.03%	5.05%
Liability for Future Policy Benefit, Current Weighted-Average Discount Rate	5.31%	5.08%