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Cash Equivalents and Marketable Securities (Tables) | 9 Months Ended
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Sep. 30, 2021
Cash Equivalents And Marketable Securities [Abstract] |
Schedule of Cash Equivalent and Marketable Securities Classified as Available-for-Sale | Cash equivalents and marketable securities classified as available-for-sale consisted of the following:
|  | September 30, 2021 |
|  | Amortized Cost Basis |  |  | Unrealized Gains |  |  | Unrealized Losses |  |  | Estimated Fair Value |
|  | (in thousands) |
Cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |
Money market funds |  | $ | 69,644 |  |  | $ | — |  |  | $ | — |  |  | $ | 69,644 |
Short-term marketable securities: |  |  |  |  |  |  |  |  |  |  |  |
U.S. treasury notes |  |  | 60,526 |  |  |  | 29 |  |  |  | — |  |  |  | 60,555 |
Commercial paper |  |  | 184,273 |  |  |  | 7 |  |  |  | (3 | ) |  |  | 184,277 |
Corporate debt securities |  |  | 134,365 |  |  |  | 10 |  |  |  | (24 | ) |  |  | 134,351 |
Supranational debt securities |  |  | 40,081 |  |  |  | 1 |  |  |  | (1 | ) |  |  | 40,081 |
Total short-term marketable securities |  |  | 419,245 |  |  |  | 47 |  |  |  | (28 | ) |  |  | 419,264 |
Total cash equivalents and marketable securities |  | $ | 488,889 |  |  | $ | 47 |  |  | $ | (28 | ) |  | $ | 488,908 |
|  | December 31, 2020 |
|  | Amortized Cost Basis |  |  | Unrealized Gains |  |  | Unrealized Losses |  |  | Estimated Fair Value |
|  | (in thousands) |
Cash equivalents: |  |  |  |  |  |  |  |  |  |  |  |
Money market funds |  | $ | 266,437 |  |  | $ | — |  |  | $ | — |  |  | $ | 266,437 |
Short-term marketable securities: |  |  |  |  |  |  |  |  |  |  |  |
U.S. treasury bills |  |  | 14,996 |  |  |  | 3 |  |  |  | — |  |  |  | 14,999 |
U.S. treasury notes |  |  | 45,292 |  |  |  | 100 |  |  |  | (1 | ) |  |  | 45,391 |
Commercial paper |  |  | 144,851 |  |  |  | — |  |  |  | — |  |  |  | 144,851 |
Corporate debt securities |  |  | 45,680 |  |  |  | 93 |  |  |  | (3 | ) |  |  | 45,770 |
Total short-term marketable securities |  |  | 250,819 |  |  |  | 196 |  |  |  | (4 | ) |  |  | 251,011 |
Total cash equivalents and marketable securities |  | $ | 517,256 |  |  | $ | 196 |  |  | $ | (4 | ) |  | $ | 517,448 |

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- Definition Cash equivalents and marketable securities. + References No definition available. + Details
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- Definition Schedule of cash equivalents and marketable securities. + References No definition available. + Details
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