Deferred Acquisition Costs - Schedule of Deferred Policy Acquisition Costs to Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024	Jun. 30, 2024	Dec. 31, 2023
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	$ 6,872,342		$ 6,495,589	$ 6,386,682
Life
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	6,035,556	$ 5,931,048	5,700,755	5,607,729	$ 5,495,593	$ 5,271,775
Life | American Income
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	3,159,464	3,078,370	2,900,229	2,829,810	2,740,138	2,573,370
Life | DTC
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	1,812,034	1,803,138	1,781,230	1,773,417	1,765,673	1,737,117
Life | Liberty National
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	773,243	757,696	728,790	712,733	696,905	666,419
Life | Other premium
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	290,815	291,844	290,506	291,769	292,877	294,869
Health
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	836,449	823,082	793,421	777,162	762,523	734,735
Health | American Income
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	83,672	81,545	76,319	74,399	71,589	66,783
Health | DTC
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	1,428	1,459	1,533	1,571	1,608	1,679
Health | Liberty National
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	152,630	152,822	148,920	146,971	145,097	139,941
Health | United American
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	68,616	69,073	70,530	71,361	71,975	73,489
Health | Family Heritage
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	530,103	$ 518,183	$ 496,119	482,860	$ 472,254	$ 452,843
Annuity Segment
Deferred Policy Acquisition Cost [Line Items]
Deferred acquisition costs	$ 337			$ 1,791