Policy Liabilities - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Liability for Future Policy Benefit, Activity [Line Items]
Change in assumptions of lapse, mortality, and morbidity, remeasurement gain (loss)	$ (46,300)	$ 3,200	$ (36,500)
Change in expected experience, remeasurement gain (loss)	(57,400)	38,000	4,600
Life
Liability for Future Policy Benefit, Activity [Line Items]
PV of expected future gross premiums	28,448,310	28,899,367	27,077,677
PV of expected future net premiums	11,757,317	12,342,307	11,748,528	$ 14,082,538
PV of expected future policy benefits, not discounted	79,213,296	77,685,477	74,660,927
Health
Liability for Future Policy Benefit, Activity [Line Items]
PV of expected future gross premiums	12,071,436	11,834,715	10,334,511
PV of expected future net premiums	6,314,148	6,089,728	5,207,422	$ 6,418,018
PV of expected future policy benefits, not discounted	$ 16,050,185	$ 15,020,883	$ 13,507,844