Cash Equivalents and Marketable Securities - Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost		$ 15,520
Cash equivalents, estimated fair value		15,520
Marketable securities, amortized cost	$ 85,738	52,645
Marketable securities, gross unrealized gains	16	60
Marketable securities, gross unrealized losses	(1)	(9)
Marketable securities, estimated fair value	85,753	52,696
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	48,128	7,023
Cash equivalents, estimated fair value	48,128	7,023
U.S. treasury securities
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	71,605
Marketable securities, gross unrealized gains	4
Marketable securities, gross unrealized losses	(1)
Marketable securities, estimated fair value	71,608
U.S. government agency securities
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	6,011
Marketable securities, gross unrealized gains	1
Marketable securities, estimated fair value	6,012
Reverse repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost		6,250
Cash equivalents, estimated fair value		6,250
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	8,122	39,714
Marketable securities, gross unrealized gains	11	45
Marketable securities, gross unrealized losses		(9)
Marketable securities, estimated fair value	$ 8,133	39,750
Commercial paper
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost		2,247
Cash equivalents, estimated fair value		2,247
Marketable securities, amortized cost		12,931
Marketable securities, gross unrealized gains		15
Marketable securities, estimated fair value		$ 12,946

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).

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-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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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).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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), classified as current.

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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 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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