Marketable Securities (Details 4) $ in Thousands	Sep. 30, 2020 USD ($)
Contractual maturities
Contractual maturities, fair value, due less than one year	$ 379,932
Contractual maturities, fair value, due from one year through three years	56,314
Contractual maturities, fair value	$ 436,246

Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant