Future policy benefits (Weighted average interest rates) (Details) - Segment Life [Member]	Mar. 31, 2024	Mar. 31, 2023
Term Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	2.90%	2.80%
Current Discount Rate	5.70%	5.70%
Whole Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	3.20%	4.00%
Current Discount Rate	4.50%	5.20%
Accident and Health Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	3.70%	3.80%
Current Discount Rate	6.30%	6.20%
Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Interest Accretion Rate	2.60%	3.80%
Current Discount Rate	3.80%	4.80%