Policy Liabilities - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Liability for Future Policy Benefit, Activity [Line Items]
Change in morality and lapse assumptions, net remeasurement gain (loss)	$ 134,300	$ 46,300	$ 5,200
Variances in expected experience, remeasurement gain (loss)	78,000	57,400	38,000
Life
Liability for Future Policy Benefit, Activity [Line Items]
Change in morality and lapse assumptions, net remeasurement gain (loss)	130,900	56,800	3,200
Variances in expected experience, remeasurement gain (loss)	61,300	50,100	31,400
Expected future gross premiums	29,644,321	28,448,310	28,899,367
Expected future net premiums	11,768,645	11,757,317	12,342,307	$ 11,748,528
Health
Liability for Future Policy Benefit, Activity [Line Items]
Change in morality and lapse assumptions, net remeasurement gain (loss)	3,400	(10,500)	(2,000)
Variances in expected experience, remeasurement gain (loss)	16,700	7,300	6,600
Expected future gross premiums	14,649,832	12,071,436	11,834,715
Expected future net premiums	$ 7,944,659	$ 6,314,148	$ 6,089,728	$ 5,207,422