Investments Realized Gains (Losses) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Debt and Equity Securities, Realized Gain (Loss) [Abstract]
Realized gains, fixed-maturity securities	$ 1,127	$ 2,372	$ 3,538	$ 3,677
Realized losses, fixed-maturity securities	(38,694)	(216)	(41,183)	(1,403)
Net realized (losses) gains from fixed-maturity securities	(37,567)	2,156	(37,645)	2,274
Realized gains, equity securities	37,406	0	48,619	2,465
Realized losses, equity securities	(258)	0	(2,948)	(1,910)
Net realized gains from equity securities	37,148	0	45,671	555
Realized gains from the sales of short-term investments and cash equivalents	0	3	3	3
Net realized investment gains (losses)	(419)	2,159	8,029	2,832
Reversal of prior-period (gains) losses on equity securities sold [Line Items]	(30,243)	25	(30,272)	134
Change in fair value of equity securities held at the end of the period	(7,526)	23,692	40,343	55,242
Change in the fair value of equity securities	$ (37,769)	$ 23,717	$ 10,071	$ 55,376

Change in fair value of equity securities held at the end of the period

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Reversal of prior-period (gains) losses on equity securities sold

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This item represents net gains (losses) realized on the sales of other short-term securities

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Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-9

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481800/320-10-50-9

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Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of realized gain from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 321
-SubTopic 10
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Amount of realized gain (loss) from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
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Amount of realized loss from sale of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Amount of unrealized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 220
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(3)(d)(2))
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-URI https://asc.fasb.org/1943274/2147477250/944-220-S99-1

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Amount of realized and unrealized gain (loss) on investment.

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-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9)(a))
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-Topic 230
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