Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net of Tax
Balance at beginning of period	$ (330,851)
Other comprehensive income (loss)
Unrealized holding gains (losses) arising during the period, net of tax	(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)
Balance at end of period	(350,238)	(330,851)
Other Comprehensive Income (Loss)
Before Tax
Balance at beginning of period	(418,799)	(578,228)	152,016
Other comprehensive income (loss)
Unrealized holding gains (losses) arising during the period, before tax	(33,861)	145,465	(740,324)
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	(9,406)	(13,737)	(9,974)
Net unrealized gains on investments	(24,455)	159,202	(730,350)
Other adjustments to comprehensive income, net	(86)	227	106
Other comprehensive income (loss)	(24,541)	159,429	(730,244)
Balance at end of period	(443,340)	(418,799)	(578,228)
Tax Effect
Balance at beginning of period	(87,948)	(121,429)	31,923
Other comprehensive income (loss)
Unrealized holding gains (losses) arising during the period, tax	(7,111)	30,548	(155,468)
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	(1,975)	(2,885)	(2,094)
Net unrealized gains on investments	(5,136)	33,433	(153,374)
Other adjustments to comprehensive income, net	(18)	48	22
Other comprehensive income (loss)	(5,154)	33,481	(153,352)
Balance at end of period	(93,102)	(87,948)	(121,429)
Net of Tax
Balance at beginning of period	(330,851)	(456,799)	120,093
Other comprehensive income (loss)
Unrealized holding gains (losses) arising during the period, net of tax	(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)
Balance at end of period	$ (350,238)	$ (330,851)	$ (456,799)