SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2022	Dec. 31, 2021
Marketable Securities, Available For Sale
Cash and cash equivalents	$ 18,341	$ 15,566
Fair Value, Recurring
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	250,630	281,203
Unrealized Losses, Marketable securities, available for sale	(2,336)	(514)
Fair Market Value, Marketable securities, available for sale	248,294	280,689
Fair Value, Recurring \| Level 1 \| Money market funds
Marketable Securities, Available For Sale
Cash and cash equivalents	18,240	15,466
Cash equivalents, Fair Market Value	18,240	15,466
Fair Value, Recurring \| Level 2 \| Commercial paper
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	43,881	58,970
Fair Market Value, Marketable securities, available for sale	43,881	58,970
Fair Value, Recurring \| Level 2 \| Asset-backed securities
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	23,096	36,681
Unrealized Losses, Marketable securities, available for sale	(140)	(42)
Fair Market Value, Marketable securities, available for sale	22,956	36,639
Fair Value, Recurring \| Level 2 \| Corporate debt securities
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	83,823	88,084
Unrealized Losses, Marketable securities, available for sale	(866)	(160)
Fair Market Value, Marketable securities, available for sale	82,957	87,924
Fair Value, Recurring \| Level 2 \| U.S. government treasury and agency securities
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	59,357	59,596
Unrealized Losses, Marketable securities, available for sale	(1,001)	(222)
Fair Market Value, Marketable securities, available for sale	58,356	59,374
Fair Value, Recurring \| Level 2 \| Supranational and sovereign government securities
Marketable Securities, Available For Sale
Amortized Cost Basis, Marketable securities, available for sale	22,233	22,406
Unrealized Losses, Marketable securities, available for sale	(329)	(90)
Fair Market Value, Marketable securities, available for sale	$ 21,904	$ 22,316

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Amount of unrealized loss 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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Amount 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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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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