Business Segments - Schedule of Assets by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Asset Reconciling Item [Line Items]
Accrued investment income	$ 269,791	$ 270,396
Deferred acquisition costs	6,495,589	6,009,477	$ 5,535,697
Goodwill	490,446	481,791
Total assets	29,076,181	28,051,499
Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and invested assets	19,736,888	19,827,199
Accrued investment income	269,791	270,396
Deferred acquisition costs	6,494,176	6,006,510
Goodwill	490,446	481,791
Business Segment Selected Assets	26,991,301	26,585,896
Corporate & Other
Segment Reporting, Asset Reconciling Item [Line Items]
Annuity and other corporate	2,084,880	1,465,603
Life
Segment Reporting, Asset Reconciling Item [Line Items]
Deferred acquisition costs	5,700,755	5,271,775	4,844,291	$ 4,412,015
Life | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and invested assets	0	0
Accrued investment income	0	0
Deferred acquisition costs	5,700,755	5,271,775
Goodwill	309,609	309,609
Business Segment Selected Assets	6,010,364	5,581,384
Health
Segment Reporting, Asset Reconciling Item [Line Items]
Deferred acquisition costs	793,421	734,735	$ 686,763	$ 649,082
Health | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and invested assets	0	0
Accrued investment income	0	0
Deferred acquisition costs	793,421	734,735
Goodwill	180,837	172,182
Business Segment Selected Assets	974,258	906,917
Investment | Operating Segments
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and invested assets	19,736,888	19,827,199
Accrued investment income	269,791	270,396
Deferred acquisition costs	0	0
Goodwill	0	0
Business Segment Selected Assets	$ 20,006,679	$ 20,097,595