Investments - Schedule of Realized Gain (Loss) on Investments (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Sales and other	$ (10,113,000)	$ (10,606,000)	$ (9,973,000)	$ (10,963,000)
Provision for credit losses	(104,000)	(39,741,000)	(16,000)	(72,508,000)
Fair value option—change in fair value	(3,691,000)	5,228,000	(19,094,000)	7,086,000
Mortgage loans	(1,280,000)	(3,579,000)	(2,154,000)	(4,859,000)
Other investments	837,000	(164,000)	1,151,000	(378,000)
Realized gains (losses) from investments	(14,351,000)	(48,862,000)	(30,086,000)	(81,622,000)
Other gains (losses)	1,762,000	3,019,000	5,698,000	4,852,000
Total realized gains (losses)	(12,589,000)	(45,843,000)	(24,388,000)	(76,770,000)
Applicable tax	2,644,000	9,627,000	5,122,000	16,122,000
Realized gains (losses), net of tax	(9,945,000)	(36,216,000)	(19,266,000)	(60,648,000)
Exchanges of fixed maturities	12,000,000.0	17,900,000	$ 78,900,000	$ 17,900,000
Exchanges of fixed maturities, net realized gains	$ 0	$ 0