Debt - Schedule of Outstanding Notes Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jan. 28, 2021	Dec. 31, 2020		Mar. 09, 2020
Liability component
Net carrying amount	$ 103,138		$ 92,421	[1]
2029 Notes
Liability component
Principal	747,500
Unamortized debt discount	(14,841)
Unamortized debt issuance costs		$ (16,100)
Net carrying amount	732,659
2027 Notes
Liability component
Principal	550,000		550,000
Unamortized debt discount	(9,964)		(158,404)
Unamortized debt issuance costs	(519)		(8,160)		$ (13,000)
Net carrying amount	$ 539,517		383,436
Equity component, net of issuance costs			$ 169,173

[1] The condensed consolidated balance sheet as of December 31, 2020 is derived from the audited consolidated financial statements as of that date.