Liability for Future Policyholder Benefits - Reconciliation of the Net Liability for Future Benefits to Life and Health Insurance Reserves (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Insurance [Abstract]
Net Liability for Future Policyholder Benefits, post-flooring	$ 2,660,300	$ 2,688,100	$ 2,660,300	$ 2,688,100
Deferred Profit Liability	444,500	374,100	444,500	374,100	$ 412,100	$ 337,800
A&H and Other Reserves	130,500	139,800	130,500	139,800
Total Life and Health Insurance Reserves	3,235,300	3,202,000	3,235,300	3,202,000
Term Life Insurance
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability for Future Policyholder Benefits, post-flooring	10,162,100	10,260,500	10,162,100	10,260,500
Expected Future Gross Premiums, undiscounted	4,015,800	4,160,200	4,015,800	4,160,200
Expected Future Gross Premiums, discounted	2,691,600	2,737,100	2,691,600	2,737,100
Gross Premiums or Assessments	98,800	99,200	200,500	200,500
Interest Expense	$ 34,400	$ 34,700	$ 69,100	$ 69,700
Interest Accretion Rate	4.50%	4.51%	4.50%	4.51%
Current Discount Rate	5.74%	5.68%	5.74%	5.68%