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Marketable Securities and Fair Value Measurements - Estimate of Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | $ 74,753 | $ 83,929
Gross Unrealized Gains | 106 | 252
Gross Unrealized Losses | (8) | (1)
Fair Value | 74,851 | 84,180
Certificates of deposit |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 2,150 | 10,548
Gross Unrealized Gains | 0 | 10
Gross Unrealized Losses | 0 | 0
Fair Value | 2,150 | 10,558
Corporate securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 45,070 | 51,745
Gross Unrealized Gains | 83 | 207
Gross Unrealized Losses | (8) | (1)
Fair Value | 45,145 | 51,951
U.S. Treasury and agency securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 9,493 | 9,222
Gross Unrealized Gains | 12 | 3
Gross Unrealized Losses | 0 | 0
Fair Value | 9,505 | 9,225
Commercial paper |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 12,136 | 500
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 | 0
Fair Value | 12,136 | 500
Asset-backed securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Amortized Cost | 5,904 | 11,914
Gross Unrealized Gains | 11 | 32
Gross Unrealized Losses | 0 | 0
Fair Value | $ 5,915 | $ 11,946

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