CASH EQUIVALENTS AND MARKETABLE SECURITIES - Schedule of Investments (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 956,183
Gross Unrealized Gains	35
Gross Unrealized Losses	(416)
Fair Value	955,802
Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	447,225
Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	508,577
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	148,943
Gross Unrealized Gains	14
Gross Unrealized Losses	0
Fair Value	148,957
Commercial paper \| Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	113,993
Commercial paper \| Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	34,964
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	179,510
Gross Unrealized Gains	7
Gross Unrealized Losses	(105)
Fair Value	179,412
Corporate notes and bonds \| Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	8,245
Corporate notes and bonds \| Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	171,167
U.S. Treasuries
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	339,973
Gross Unrealized Gains	14
Gross Unrealized Losses	(3)
Fair Value	339,984
U.S. Treasuries \| Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	324,987
U.S. Treasuries \| Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	14,997
U.S. Government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	287,757
Gross Unrealized Gains	0
Gross Unrealized Losses	(308)
Fair Value	287,449
U.S. Government agencies \| Cash and Cash Equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	0
U.S. Government agencies \| Marketable Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 287,449

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).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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Amount, before tax, of unrealized loss 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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-Paragraph 2
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Amortized cost excluding accrued interest, after allowance for credit loss, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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