Schedule IV. Reinsurance (Details) - USD ($) $ in Thousands		12 Months Ended
	Mar. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Life insurance in force, gross amount		$ 229,804,503	$ 227,975,584	$ 225,286,002
Life insurance in force, ceded to other companies		430,278	671,056	685,289
Life insurance in force, assumed from other companies		1,734,812	1,823,957	1,996,223
Life insurance in force, net amount		$ 231,109,037	$ 229,128,485	$ 226,596,936
Life insurance in force, percentage of amount assumed to net		0.80%	0.80%	0.90%
Premium, gross amount		$ 4,810,378	$ 4,619,824	$ 4,391,558
Premium, ceded to other companies		(39,840)	7,098	7,317
Premium, assumed from other companies		28,332	41,288	58,877
Premium, net amount		$ 4,878,550	$ 4,654,014	$ 4,443,118
Percentage of amount assumed to net		0.60%	0.90%	1.30%
Recaptures netted against ceded premiums	$ 39,000	$ 39,000	$ 0	$ 0
Policy charges		11,700	12,300	12,900
Life insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Premium, gross amount		3,294,163	3,235,744	3,109,838
Premium, ceded to other companies		(39,968)	4,649	4,597
Premium, assumed from other companies		17,669	17,994	19,104
Premium, net amount		$ 3,351,800	$ 3,249,089	$ 3,124,345
Percentage of amount assumed to net		0.50%	0.60%	0.60%
Health insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Line Items]
Premium, gross amount		$ 1,516,215	$ 1,384,080	$ 1,281,720
Premium, ceded to other companies		128	2,449	2,720
Premium, assumed from other companies		10,663	23,294	39,773
Premium, net amount		$ 1,526,750	$ 1,404,925	$ 1,318,773
Percentage of amount assumed to net		0.70%	1.70%	3.00%