Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 604,440	$ 603,119	$ 742,934
Other comprehensive income (loss), net of tax (Note 15)
Unrealized holding gains (losses) on investments arising during the period for which an allowance for expected losses has not been recognized	(26,750)	114,917	(584,856)
Less: Reclassification adjustment for net gains (losses) on investments included in net income
Net realized gains (losses) on disposals and non-credit related impairment losses	(7,431)	(10,852)	(7,880)
Net unrealized gains (losses) on investments	(19,319)	125,769	(576,976)
Other adjustments to comprehensive income (loss), net	(68)	179	84
Other comprehensive income (loss), net of tax	(19,387)	125,948	(576,892)
Comprehensive income (loss)	$ 585,053	$ 729,067	$ 166,042