Cash, Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cash and cash equivalents
Amortized Cost	$ 10,998	$ 4,789
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Fair Value	10,998	4,789
Cash and cash equivalents \| Money market funds
Amortized Cost	10,998	4,789
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Fair Value	10,998	4,789
Marketable securities
Amortized Cost	33,520	41,510
Gross Unrealized Gains	217	23
Gross Unrealized Loss	0	(2)
Fair Value	33,737	41,531
Marketable securities \| US Treasury securities
Amortized Cost	33,520	41,510
Gross Unrealized Gains	217	23
Gross Unrealized Loss	0	(2)
Fair Value	33,737	41,531
Short-term deposits
Amortized Cost	15,000	10,000
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Fair Value	15,000	10,000
Short-term deposits \| Term bank deposits
Amortized Cost	15,000	10,000
Gross Unrealized Gains	0	0
Gross Unrealized Loss	0	0
Fair Value	$ 15,000	$ 10,000

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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- Definition

Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

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- Definition

Amortized cost 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 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27161-111563

Reference 2: 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

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Amount of investment in debt security measured at amortized cost (held-to-maturity), investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and investment in debt security measured at fair value with change in fair value recognized in net income (trading).

+ References

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