Cash Equivalents and Marketable Securities - Schedule of Estimated Fair Value of Cash Equivalents and Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	$ 53,804	$ 15,520
Cash equivalents, estimated fair value	53,804	15,520
Marketable securities, amortized cost	91,978	52,645
Marketable securities, gross unrealized gains	44	60
Marketable securities, gross unrealized losses	(5)	(9)
Marketable securities, estimated fair value	92,017	52,696
Money market funds
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	43,306	7,023
Cash equivalents, estimated fair value	43,306	7,023
U.S. treasury securities
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	5,499
Cash equivalents, estimated fair value	5,499
Marketable securities, amortized cost	65,966
Marketable securities, gross unrealized gains	3
Marketable securities, gross unrealized losses	(4)
Marketable securities, estimated fair value	65,965
U.S. government agency securities
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost	4,999
Cash equivalents, estimated fair value	4,999
Marketable securities, amortized cost	5,535
Marketable securities, estimated fair value	5,535
Reverse repurchase agreements
Schedule Of Available For Sale Securities [Line Items]
Cash equivalents, amortized cost		6,250
Cash equivalents, estimated fair value		6,250
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	1,748	12,931
Marketable securities, gross unrealized gains	3	15
Marketable securities, estimated fair value	1,751	12,946
Corporate bonds
Schedule Of Available For Sale Securities [Line Items]
Marketable securities, amortized cost	18,729	39,714
Marketable securities, gross unrealized gains	38	45
Marketable securities, gross unrealized losses	(1)	(9)
Marketable securities, estimated fair value	$ 18,766	$ 39,750

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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-Section 50
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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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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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