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FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS - Cash and Cash Equivalents and Short-term Investments (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
--- | --- | ---
Fair value disclosure |  |
Cash and cash equivalents | $ 251,503 | $ 158,264
Short-term investments | 89,326 | 167,662
Concentrations of Credit Risk of Financial Instruments |  |
Cash deposits and short-term investments which were neither FDIC insured nor direct obligations of the U.S. government | 70,200 | 87,600
Cash deposits |  |
Fair value disclosure |  |
Cash and cash equivalents | 160,671 | 137,247
Variable rate demand notes |  |
Fair value disclosure |  |
Cash and cash equivalents |  | 9,285
Money market funds |  |
Fair value disclosure |  |
Cash and cash equivalents | 90,832 | 11,732
Certificates of deposit |  |
Fair value disclosure |  |
Short-term investments | 69,421 | 88,851
U.S. Treasury securities |  |
Fair value disclosure |  |
Short-term investments | $ 19,905 | $ 78,811

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