v3.20.2

Marketable Securities - Summary of Available-for-sale Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	$ 1,294,147	$ 176,627
Marketable securities, Unrealized Gain	2,278	56
Marketable securities, Unrealized Losses	(164)	(9)
Marketable securities, Fair Value	1,296,261	176,674
Commercial Debt Securities
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	965,398	80,376
Marketable securities, Unrealized Gain	1,784	46
Marketable securities, Unrealized Losses	(154)	(5)
Marketable securities, Fair Value	967,028	80,417
Certificates of Deposit
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	34,225
Marketable securities, Unrealized Gain	37
Marketable securities, Fair Value	34,262
U.S. Government Treasury Securities
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	169,306	72,467
Marketable securities, Unrealized Gain	427	10
Marketable securities, Unrealized Losses	(2)	(4)
Marketable securities, Fair Value	169,731	72,473
Commercial Paper
Marketable Securities [Line Items]
Marketable securities, Amortized Cost	125,218	23,784
Marketable securities, Unrealized Gain	30
Marketable securities, Unrealized Losses	(8)
Marketable securities, Fair Value	$ 125,240	$ 23,784

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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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