Investments and Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Assets, Fair Value Disclosure [Abstract]
Investments, amortized cost	$ 5,703	$ 5,966
Fair Value, Transfers Between Level 1 and Level 2, Description and Policy [Abstract]
Transfer from Level 1 to Level 2 , assets	0
Transfer from Level 2 to Level 1 , assets	0
Transfers into Level 3, assets	0
Transfer out of Level 3, assets	0
Recurring
Assets, Fair Value Disclosure [Abstract]
Total	5,703	5,966
Recurring \| Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	2,643	2,885
Recurring \| Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, amortized cost	3,060	3,081
Recurring \| Significant Other Observable Inputs (Level 2)
Assets, Fair Value Disclosure [Abstract]
Total	5,703	5,966
Recurring \| Significant Other Observable Inputs (Level 2) \| Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Cash and cash equivalents, fair value disclosure	2,643	2,885
Recurring \| Significant Other Observable Inputs (Level 2) \| Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments, amortized cost	$ 3,060	$ 3,081

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
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Amount of 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of transfers of assets measured on a recurring basis out of Level 1 of the fair value hierarchy into Level 2.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 820
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-Section 50
-Paragraph 2
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Amount of transfers of assets measured on a recurring basis out of Level 2 of the fair value hierarchy into Level 1.

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

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