Fair Value - Level 3 Assets (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	$ 16,398	$ 59,395	$ 22,559	$ 31,881
Included in earnings	(139)	(880)	(525)	(1,772)
Included in other comprehensive income (loss)	67	(2,149)	385	(3,530)
Purchases	2,661	753	6,606	10,574
Sales	(884)	(7,781)	(1,922)	(16,911)
Transfers into Level 3	2,208	4,747	5,860	52,396
Transfers out of Level 3	(4,838)	(35,933)	(17,490)	(54,486)
Ending balance	15,473	18,152	15,473	18,152
Available-for-sale Securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	11,668	57,529	18,780	29,798
Included in earnings	(172)	(862)	(551)	(1,537)
Included in other comprehensive income (loss)	67	(2,149)	385	(3,530)
Purchases	1,661	753	4,648	10,574
Sales	(884)	(7,781)	(1,922)	(16,911)
Transfers into Level 3	2,208	4,747	5,860	52,396
Transfers out of Level 3	(3,031)	(35,933)	(15,683)	(54,486)
Ending balance	11,517	16,304	11,517	16,304
Corporate debt securities \| Available-for-sale Securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	5,123	6,109	3,686	5,256
Included in earnings	10	(7)	(4)	(2)
Included in other comprehensive income (loss)	123	(28)	245	(417)
Purchases	1,661	753	3,193	5,687
Sales	(511)	(495)	(1,256)	(3,614)
Transfers into Level 3	730	2,899	3,883	8,673
Transfers out of Level 3	(3,031)	(1,956)	(5,642)	(8,308)
Ending balance	4,105	7,275	4,105	7,275
Commercial mortgage-backed securities \| Available-for-sale Securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	6,533	8,871	10,910	15,728
Included in earnings	(182)	(188)	(542)	(892)
Included in other comprehensive income (loss)	(56)	(413)	44	(1,071)
Purchases	0	0	1,455	0
Sales	(366)	(660)	(551)	(3,825)
Transfers into Level 3	1,478	1,174	1,944	5,509
Transfers out of Level 3	0	(3,417)	(5,853)	(10,082)
Ending balance	7,407	5,367	7,407	5,367
Residential mortgage- backed securities \| Available-for-sale Securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	12	42,549	4,184	8,814
Included in earnings	0	(667)	(5)	(643)
Included in other comprehensive income (loss)	0	(1,708)	96	(2,042)
Purchases	0	0	0	4,887
Sales	(7)	(6,626)	(115)	(9,472)
Transfers into Level 3	0	674	33	38,214
Transfers out of Level 3	0	(30,560)	(4,188)	(36,096)
Ending balance	5	3,662	5	3,662
Equity securities \| Equity securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	4,730	1,866	3,779	2,083
Included in earnings	33	(18)	26	(235)
Included in other comprehensive income (loss)	0	0	0	0
Purchases	1,000	0	1,958	0
Sales	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	(1,807)	0	(1,807)	0
Ending balance	$ 3,956	$ 1,848	$ 3,956	$ 1,848

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
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-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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