Fair Value of Financial Instruments - Level 3 Securities (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 1,593	$ 1,771
Net unrealized gains (losses)	43	(35)
Transfers out		(100)
Ending balance	1,636	1,636
Corporate bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	150	250
Net unrealized gains (losses)	0	0
Transfers out		(100)
Ending balance	150	150
Asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	848	926
Net unrealized gains (losses)	43	(35)
Transfers out		0
Ending balance	891	891
Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	595	595
Net unrealized gains (losses)	0	0
Transfers out		0
Ending balance	$ 595	$ 595

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 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=123874694&loc=d3e19207-110258

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- Definition

Amount of transfers of financial instrument classified as an asset out of 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=123874694&loc=d3e19207-110258

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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