Cash and Investments in Marketable Securities - Schedule of Portfolio of Cash and Investments in Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	$ 763,287
Gross Unrealized Gains	12	$ 1,100
Gross Unrealized Losses	(674)	(200)
Fair Value	762,625	1,003,348
Cash	1,250	6,285
Total cash and investments in marketable securities	798,783	1,198,558
Corporate notes and bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	278,475
Gross Unrealized Gains	7
Gross Unrealized Losses	(361)
Fair Value	278,121	687,469
Corporate commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	478,932
Gross Unrealized Gains	5
Gross Unrealized Losses	(308)
Fair Value	478,629	313,497
Obligations of U.S. government agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	5,880
Gross Unrealized Gains	0
Gross Unrealized Losses	(5)
Fair Value	5,875	2,382
Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	23,968	179,302
Certificates of deposit | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in marketable securities	$ 10,940	$ 9,623