Future policy benefits (Premiums & interest) (Details) - Segment Life [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	$ 5,037	$ 4,305
Interest Accretion	309	266
Term Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	542	509
Interest Accretion	15	14
Whole Life Insurance
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	2,024	1,504
Interest Accretion	184	149
Accident and Health Insurance Product Line [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	2,314	2,250
Interest Accretion	98	95
Insurance, Other
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	157	42
Interest Accretion	$ 12	$ 8