Future policy benefits (Premiums & interest) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	$ 4,769	$ 3,144
Interest Accretion	221	153
Term Life Insurance | Segment Life [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	511	361
Interest Accretion	9	7
Whole Life Insurance | Segment Life [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	858	411
Interest Accretion	114	86
Accident and Health Insurance Product Line [Member] | Segment Life [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	2,171	1,226
Interest Accretion	93	58
Accident and Health Insurance Product Line [Member] | Overseas General Insurance [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	1,175	1,075
Interest Accretion	0	0
Insurance, Other | Segment Life [Member]
Liability for Future Policy Benefit, Activity [Line Items]
Gross Premiums or Assessments	54	71
Interest Accretion	$ 5	$ 2