Policy Liabilities - Schedule of Weighted Average Duration of Liability For Future Policy Benefits (Details)	Sep. 30, 2025	Sep. 30, 2024
Life | American Income
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	22 years 5 months 1 day	22 years 9 months 21 days
At current discount rates	22 years 3 months 25 days	23 years 10 days
Life | DTC
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	18 years 9 months 29 days	19 years 5 months 1 day
At current discount rates	19 years 8 months 26 days	20 years 9 months 21 days
Life | Liberty National
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	15 years 3 months 14 days	15 years 3 months 21 days
At current discount rates	15 years 3 months 7 days	15 years 9 months 18 days
Life | Other premium
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	15 years 7 months 24 days	16 years 25 days
At current discount rates	16 years 5 months 15 days	17 years 5 months 23 days
Health | American Income
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	13 years 3 months 3 days	12 years 6 months
At current discount rates	13 years 3 months 14 days	12 years 10 months 20 days
Health | DTC
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	12 years 5 months 8 days	11 years 8 months 23 days
At current discount rates	11 years 3 months 7 days	10 years 11 months 4 days
Health | Liberty National
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	9 years 5 months 23 days	9 years 3 months 3 days
At current discount rates	9 years 4 months 20 days	9 years 5 months 23 days
Health | United American
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	12 years 5 months 8 days	11 years 8 months 23 days
At current discount rates	11 years 3 months 7 days	10 years 11 months 4 days
Health | Family Heritage
Liability for Future Policy Benefit, Activity [Line Items]
At original discount rates	16 years 3 months 7 days	15 years 4 months 2 days
At current discount rates	15 years 14 days	14 years 7 months 6 days