Reserve for Future Policy Benefits and Contractholder Funds - Schedule of Key Assumptions Used in Calculating the Reserve for Future Policy Benefits (Details)	Dec. 31, 2023	Dec. 31, 2022
Accident and health
Liability for Future Policy Benefit, Activity [Line Items]
Weighted-average duration (in years)	4 years	3 years 7 months 6 days
Interest accretion rate (discount rate at contract issuance)	5.83%	4.97%
Current discount rate (upper-medium grade fixed income yield)	4.77%	4.72%
Traditional life
Liability for Future Policy Benefit, Activity [Line Items]
Weighted-average duration (in years)	15 years	13 years 9 months 18 days
Interest accretion rate (discount rate at contract issuance)	5.41%	5.56%
Current discount rate (upper-medium grade fixed income yield)	4.97%	5.23%