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Available-for-Sale Investments (Tables) | 12 Months Ended
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Dec. 31, 2019
Investments Debt And Equity Securities [Abstract] |
Summary of Available-for-Sale Securities Held | The following tables summarize the available-for-sale securities held at December 31, 2019 and 2018 (in thousands):
December 31, 2019 |  | Amortized cost |  |  | Gross unrealized gains |  |  | Gross unrealized losses |  |  | Fair Value |
Commercial paper |  | $ | 20,484 |  |  | $ | 18 |  |  | $ | (1 | ) |  | $ | 20,501 |
Corporate debt securities |  |  | 71,288 |  |  |  | 96 |  |  |  | (1 | ) |  |  | 71,383 |
U.S. government agency securities |  |  | 9,005 |  |  |  | 2 |  |  |  | (2 | ) |  |  | 9,005 |
Total |  | $ | 100,777 |  |  | $ | 116 |  |  | $ | (4 | ) |  | $ | 100,889 |
December 31, 2018 |  | Amortized cost |  |  | Gross unrealized gains |  |  | Gross unrealized losses |  |  | Fair Value |
Commercial paper |  | $ | 53,549 |  |  | $ | — |  |  | $ | (47 | ) |  | $ | 53,502 |
Corporate debt securities |  |  | 54,022 |  |  |  | 4 |  |  |  | (23 | ) |  |  | 54,003 |
U.S. government agency securities |  |  | 3,971 |  |  |  | 1 |  |  |  | — |  |  |  | 3,972 |
Total |  | $ | 111,542 |  |  | $ | 5 |  |  | $ | (70 | ) |  | $ | 111,477 |

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- Definition Tabular disclosure of the reconciliation of available-for-sale securities from cost basis to fair value. + References No definition available. + Details
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