CASH, CASH EQUIVALENTS AND INVESTMENTS - Schedule of Short-Term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	$ 253,759	$ 99,929
Available-for-sale Securities, Gross Unrealized Gains	43	67
Available-for-sale Securities, Gross Unrealized Losses	(16)
Available-for-sale Securities, Fair Value Disclosure	253,786	99,996
Certificates of Deposit [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	480
Available-for-sale Securities, Fair Value Disclosure	480
Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis	253,279
Available-for-sale Securities, Gross Unrealized Gains	43
Available-for-sale Securities, Gross Unrealized Losses	(16)
Available-for-sale Securities, Fair Value Disclosure	$ 253,306
U.S. Government Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Debt Securities, Amortized Cost Basis		99,929
Available-for-sale Securities, Gross Unrealized Gains		67
Available-for-sale Securities, Fair Value Disclosure		$ 99,996

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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