Fair Value - Level 3 Assets (Details) - Level 3 - Available-for-sale securities - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	$ 11,645	$ 12,577
Included in earnings	(1)	9
Included in other comprehensive income	(1,526)	268
Purchases	2,030	2,133
Sales	(513)	(437)
Transfers into Level 3	11,452	5,519
Transfers out of Level 3	(3,648)	(6,449)
Ending balance	19,439	13,620
Corporate debt securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	8,324	12,577
Included in earnings	7	11
Included in other comprehensive income	(1,378)	268
Purchases	1,718	734
Sales	(427)	(431)
Transfers into Level 3	6,895	4,813
Transfers out of Level 3	(3,083)	(6,449)
Ending balance	12,056	11,523
Residential mortgage-backed securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance		0
Included in earnings		0
Included in other comprehensive income		0
Purchases		921
Sales		(6)
Transfers into Level 3		0
Transfers out of Level 3		0
Ending balance		915
Commercial mortgage-backed securities
Roll forward of level 3 fair value measurements on a recurring basis
Beginning balance	3,321	0
Included in earnings	(8)	(2)
Included in other comprehensive income	(148)	0
Purchases	312	478
Sales	(86)	0
Transfers into Level 3	4,557	706
Transfers out of Level 3	(565)	0
Ending balance	$ 7,383	$ 1,182

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

No definition available.

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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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
-Publisher FASB
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-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
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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.

+ References

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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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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-Publisher FASB
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-Section 50
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