Cash and Cash Equivalents, and Investments and Fair Value Measurements - Schedule of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	$ 2,265,451
Fair Value	2,261,528
Cash and cash equivalents:
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	854,078	$ 479,853
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	854,078	479,853
Cash and cash equivalents: \| Cash
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	30,324	15,054
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	30,324	15,054
Cash and cash equivalents: \| Money market funds \| Level 1
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	823,754	464,799
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	823,754	464,799
Short-term investments:
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	692,320	664,119
Unrealized Gain	40	1,502
Unrealized Loss	(579)	(54)
Fair Value	691,781	665,567
Short-term investments: \| Commercial paper \| Level 2
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	124,211	204,152
Unrealized Gain	2	24
Unrealized Loss	(33)	(6)
Fair Value	124,180	204,170
Short-term investments: \| Corporate debt securities \| Level 2
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	552,609	459,967
Unrealized Gain	36	1,478
Unrealized Loss	(546)	(48)
Fair Value	552,099	461,397
Short-term investments: \| Agency bonds \| Level 2
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	15,500
Unrealized Gain	2
Unrealized Loss	0
Fair Value	15,502
Long-term investments:
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	749,377	523,270
Unrealized Gain	0	641
Unrealized Loss	(3,384)	(283)
Fair Value	745,993	523,628
Long-term investments: \| Corporate debt securities \| Level 2
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	724,517	484,275
Unrealized Gain	0	605
Unrealized Loss	(3,277)	(283)
Fair Value	721,240	484,597
Long-term investments: \| Agency bonds \| Level 2
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost		38,995
Unrealized Gain		36
Unrealized Loss		0
Fair Value		$ 39,031
Long-term investments: \| U.S. treasury securities \| Level 1
Schedule Of Available For Sale Securities [Line Items]
Adjusted Cost	24,860
Unrealized Gain	0
Unrealized Loss	(107)
Fair Value	$ 24,753

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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