Investments in Equity Securities (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 1,078,092	$ 1,090,347
Fair Value
Debt Securities, Available-for-sale [Line Items]
Cost	977,983	949,332
Gross Unrealized, Gains	158,908	194,881
Gross Unrealized, Losses	(58,799)	(53,866)
Equity securities	1,078,092	1,090,347
Fair Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Cost	603,574	664,997
Gross Unrealized, Gains	139,146	191,806
Gross Unrealized, Losses	(46,165)	(18,749)
Equity securities	696,555	838,054
Fair Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Cost	374,409	284,335
Gross Unrealized, Gains	19,762	3,075
Gross Unrealized, Losses	(12,634)	(35,117)
Equity securities	381,537	252,293
Carrying Value
Debt Securities, Available-for-sale [Line Items]
Equity securities	1,078,092	1,090,347
Carrying Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Equity securities	696,555	838,054
Carrying Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Equity securities	$ 381,537	$ 252,293