OTHER COMPREHENSIVE INCOME (LOSS) - Reclassifications Out of AOCI Into Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized and unrealized investment gains (losses)	$ 46,200	$ (40,360)	$ 20,850	$ (54,223)
Impairment losses	(400)	(156)	(2,326)	(164)
Income before income taxes and interest in income (loss) of equity method investments	280,262	244,611	516,362	514,249
Income tax (expense) benefit	(56,199)	(40,547)	(100,521)	84,107
Net income	223,358	211,964	417,427	607,425
Unrealized gains (losses) on available for sale investments | Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of accumulated comprehensive income into net income available to common shareholders [Line Items]
Other realized and unrealized investment gains (losses)	(10,606)	(59,340)	(42,990)	(84,211)
Impairment losses	(400)	(156)	(2,326)	(164)
Income before income taxes and interest in income (loss) of equity method investments	(11,006)	(59,496)	(45,316)	(84,375)
Income tax (expense) benefit	1,484	5,124	7,654	6,588
Net income	$ (9,522)	$ (54,372)	$ (37,662)	$ (77,787)