Reserve for Future Policy Benefits and Contractholder Funds - Schedule of Revenue and Interest Recognized (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Revenues	$ 711	$ 677
Interest expense	33	37
Accident and health insurance
Liability for Future Policy Benefit, Activity [Line Items]
Revenues	605	600
Interest expense	21	27
Traditional life
Liability for Future Policy Benefit, Activity [Line Items]
Revenues	106	77
Interest expense	$ 12	$ 10