Investments in Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 31, 2025	Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Equity securities		$ 1,262,192	$ 1,203,788
Fair Value
Debt Securities, Available-for-sale [Line Items]
Cost		916,801	941,974
Gross Unrealized, Gains	$ 346,697	370,285
Gross Unrealized, Losses	(84,883)	(24,894)
Equity securities		1,262,192	1,203,788
Fair Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Cost		528,148	612,479
Gross Unrealized, Gains	223,981	211,335
Gross Unrealized, Losses	(76,293)	(19,913)
Equity securities		719,570	760,167
Fair Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Cost		388,653	329,495
Gross Unrealized, Gains	122,716	158,950
Gross Unrealized, Losses	$ (8,590)	(4,981)
Equity securities		542,622	443,621
Carrying Value
Debt Securities, Available-for-sale [Line Items]
Equity securities		1,262,192	1,203,788
Carrying Value | Common stock
Debt Securities, Available-for-sale [Line Items]
Equity securities		719,570	760,167
Carrying Value | Preferred stocks
Debt Securities, Available-for-sale [Line Items]
Equity securities		$ 542,622	$ 443,621