Investments (Maturity Distribution) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale, Amortized Cost
Due in one year or less	$ 14,657
Available-for-sale Securities, Debt Maturities, Due After One Year Through Five Years, Amortized Cost Basis	129,118
Available-for-sale Securities, Debt Maturities, Due After Five Years Through Ten Years, Amortized Cost Basis	274,759
Available-for-sale Securities, Debt Maturities, Due After Ten Years, Amortized Cost Basis	970,856
Debt Securities, Available-for-sale, Amortized Cost	1,389,390	$ 1,381,318
Debt Securities, Available-for-sale, Fair Value
Due in one year or less	14,514
Available-for-sale Securities, Debt Maturities, Due After One Year Through Five Years, Fair Value	125,520
Available-for-sale Securities, Debt Maturities, Due After Five Years Through Ten Years, Fair Value	255,800
Available-for-sale Securities, Debt Maturities, Due After Ten Years, Fair Value	755,519
Fixed maturity securities, available-for-sale	$ 1,151,353	$ 1,179,619

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
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-URI https://asc.fasb.org//1943274/2147479130/326-30-45-1

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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