Investments - Schedule of Pretax Net Realized Investment Gains (Losses) and Net Changes in Unrealized Gains (Losses) on Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net realized gains (losses):
Net realized gains (losses) - Available-for-sale	$ (2,997)	$ 1,859	$ 3,872
Net realized gains (losses) - Equity securities	20,287	62,512	15,796
Net realized gains (losses) - Investment in unconsolidated investees	570,952	(61)	(187)
Net realized gains (losses) - Other	273	(88)	(1,596)
Total net realized gains (losses)	588,515	64,222	17,885
Net unrealized gains (losses) on equity securities	(121,037)	65,258	32,101
Unrealized gains (losses) recognized in other comprehensive earnings - Available-for-sale	(341,944)	(71,538)	67,350
Unrealized gains (losses) recognized in other comprehensive earnings - Investment in unconsolidated investees	(10,994)	(3,047)	3,444
Unrealized gains (losses) recognized in other comprehensive earnings - Other	(102)	44	369
Total unrealized gains (losses) recognized in other comprehensive earnings	(353,040)	(74,541)	71,163
Net realized gains (losses) and changes in unrealized gains (losses) on investments	114,438	54,939	121,149
Equity Securities
Net realized gains (losses):
Net unrealized gains (losses) on equity securities	(118,912)	58,459	32,317
Other
Net realized gains (losses):
Net unrealized gains (losses) on equity securities	$ (2,125)	$ 6,799	$ (216)