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FAIR VALUE MEASUREMENTS - SECURITY TYPE (Details) - USD ($) $ in Thousands | Mar. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Included in cash and cash equivalents: |  |
Amortized Cost | $ 27,577 | $ 31,706
Gross Unrealized Losses | (1) |
Estimated Fair Value | 27,576 | 31,706
Restricted cash: |  |
Amortized Cost | 364 | 364
Estimated Fair Value | 364 | 364
Marketable securities: |  |
Amortized Cost | 147,001 | 177,675
Gross Unrealized Gains |  | 4
Gross Unrealized Losses | (711) | (177)
Estimated Fair Value | 146,290 | 177,502
Money market funds |  |
Included in cash and cash equivalents: |  |
Amortized Cost | 15,327 | 24,207
Estimated Fair Value | 15,327 | 24,207
Restricted cash: |  |
Amortized Cost | 93 | 93
Estimated Fair Value | 93 | 93
Commercial paper |  |
Included in cash and cash equivalents: |  |
Amortized Cost | 7,999 | 7,499
Estimated Fair Value | 7,999 | 7,499
Corporate notes |  |
Included in cash and cash equivalents: |  |
Amortized Cost | 4,251 |
Gross Unrealized Losses | (1) |
Estimated Fair Value | 4,250 |
Certificate of deposit |  |
Restricted cash: |  |
Amortized Cost | 271 | 271
Estimated Fair Value | 271 | 271
U.S. Treasury securities (due in less than one year) |  |
Marketable securities: |  |
Amortized Cost | 20,650 | 15,585
Gross Unrealized Losses | (107) | (18)
Estimated Fair Value | 20,543 | 15,567
U.S. Treasury securities (due in one to two years) |  |
Marketable securities: |  |
Amortized Cost |  | 1,524
Gross Unrealized Losses |  | (3)
Estimated Fair Value |  | 1,521
Municipal securities (due in less than one year) |  |
Marketable securities: |  |
Amortized Cost | 3,000 |
Gross Unrealized Losses | (53) |
Estimated Fair Value | 2,947 |
Municipal securities (due in one to two years) |  |
Marketable securities: |  |
Amortized Cost |  | 3,000
Gross Unrealized Losses |  | (15)
Estimated Fair Value |  | 2,985
Government-sponsored enterprise securities (due in less than one year) |  |
Marketable securities: |  |
Amortized Cost | 6,500 | 12,500
Gross Unrealized Losses | (39) | (7)
Estimated Fair Value | 6,461 | 12,493
Commercial paper (due in less than one year) |  |
Marketable securities: |  |
Amortized Cost | 69,434 | 84,398
Gross Unrealized Gains |  | 2
Gross Unrealized Losses | (233) | (38)
Estimated Fair Value | 69,201 | 84,362
Corporate notes (due in less than one year) |  |
Marketable securities: |  |
Amortized Cost | 36,404 | 36,444
Gross Unrealized Gains |  | 2
Gross Unrealized Losses | (211) | (17)
Estimated Fair Value | 36,193 | 36,429
Corporate notes (due in one to two years) |  |
Marketable securities: |  |
Amortized Cost | 11,013 | 24,224
Gross Unrealized Losses | (68) | (79)
Estimated Fair Value | $ 10,945 | $ 24,145

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