CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME(UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 211,964	$ 150,674	$ 607,425	$ 330,773
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) arising during the period, net of reclassification adjustment	18,684	(61,796)	(18,378)	127,143
Foreign currency translation adjustment	(1,803)	3,183	(10,754)	2,648
Total other comprehensive income (loss), net of tax	16,881	(58,613)	(29,132)	129,791
Comprehensive income	228,845	92,061	578,293	460,564
Unrealized gains (losses) on available for sale investments
Other comprehensive income (loss), net of tax:
Adjustment for reclassification of net realized (gains) losses and impairment losses recognized in net income	54,372	36,621	77,787	77,370
Unrealized gains (losses) arising during the period, net of reclassification adjustment	18,684	(61,796)	(18,378)	127,143
Unrealized gains (losses) on available for sale investments | Unrealized gains (losses) arising during the period for which an allowance for expected credit losses has not been recognized
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) arising during period	(35,586)	(98,402)	(95,602)	41,700
Unrealized gains (losses) on available for sale investments | Unrealized gains (losses) arising during the period for which an allowance for expected credit losses has been recognized
Other comprehensive income (loss), net of tax:
Unrealized gains (losses) arising during period	$ (102)	$ (15)	$ (563)	$ 8,073