Future policy benefits (Weighted average interest rates) (Details) - Segment Life [Member]	Sep. 30, 2024	Sep. 30, 2023
Term Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	3.00%	2.90%
Current Discount Rate	5.20%	6.00%
Whole Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	3.20%	3.20%
Current Discount Rate	4.10%	4.70%
Accident and Health Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	3.80%	3.70%
Current Discount Rate	5.80%	6.70%
Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	2.70%	2.60%
Current Discount Rate	3.80%	4.30%