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Summary of Significant Accounting Policies - Summary of Assets Measured at Fair Value on Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands | Dec. 31, 2019 | Dec. 31, 2018
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Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | $ 91,473 | $ 108,028
Money Market Funds | Cash and Cash Equivalents |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | 33,774 | 6,804
U.S. Treasury Securities | Cash and Cash Equivalents |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis |  | 238
U.S. Treasury Securities | Marketable Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | 57,699 | 100,986
Active Markets (Level 1) |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | 91,473 | 108,028
Active Markets (Level 1) | Money Market Funds | Cash and Cash Equivalents |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | 33,774 | 6,804
Active Markets (Level 1) | U.S. Treasury Securities | Cash and Cash Equivalents |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis |  | 238
Active Markets (Level 1) | U.S. Treasury Securities | Marketable Securities |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |
Assets measured at fair value on a recurring basis | $ 57,699 | $ 100,986

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- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + 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 (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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