Fair Value Measurements (Tables)

9 Months Ended

12 Months Ended

Sep. 30, 2021

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Summary of company's financial instruments that were measured at fair value by level within the fair value hierarchy on a recurring basis

The following table sets forth the Company’s financial instruments that were measured at fair value by level within the fair value hierarchy on a recurring basis as of the dates indicated (in thousands):

					As of December 31, 2020
	Balance Sheet Location		Total		Level 1		Level 2		Level 3
Financial Assets:
Money market funds		Cash and cash equivalents	$	6,413	$	6,413	$	—	$	—
Embedded derivative		Long-term debt		5,680		—		—		5,680
Total financial assets			$	12,093	$	6,413	$	—	$	5,680
Financial Liability:
Convertible security		Deferred acquisition costs, current	$	46,500	$	—	$	—	$	46,500
					As of September 30, 2021
	Balance Sheet Location		Total		Level 1		Level 2		Level 3
Financial Assets:
Money market funds		Cash and cash equivalents	$	820,594	$	820,594	$	—	$	—
Marketable equity securities		Prepaid expenses and other current assets		5,165		5,165
Total financial assets			$	825,759	$	825,759	$	—	$	—
Financial Liability:
Convertible security		Deferred acquisition costs, current	$	25,000	$	25,000	$	—	$	—

The following table sets forth the Company’s financial instruments that were measured at fair value by level within the fair value hierarchy on a recurring basis as of the dates indicated (in thousands):

					As of December 31, 2019
	Balance Sheet Location		Total		Level 1		Level 2		Level 3
Financial Asset:
Money market funds		Cash and cash equivalents	$	340,532	$	340,532	$	—	$	—
Financial Liability:
Interest rate swap		Accrued liabilities	$	5,336	$	—	$	5,336	$	—
					As of December 31, 2020
	Balance Sheet Location		Total		Level 1		Level 2		Level 3
Financial Assets:
Money market funds		Cash and cash equivalents	$	6,413	$	6,413	$	—	$	—
Embedded derivative		Long-term debt		5,680		—		—		5,680
Total financial assets			$	12,093	$	6,413	$	—	$	5,680
Financial Liability:
Convertible security		Deferred acquisition costs, current	$	46,500	$	—	$	—	$	46,500

Summary of reconciliation of the Company's financial asset and liability measured at fair value

The following table presents a reconciliation of the Company’s financial asset and liability measured at fair value as of September 30, 2021 using significant unobservable inputs (Level 3), and the change in fair value (in thousands):

	Embedded Derivative			Convertible Security
Balance as of December 31, 2020	$	5,680		$	46,500
Addition related to the issuance of term loans in February 2021		5,630			—
Extinguishment of term loans in February 2021		(1,130	)		—
Change in fair value recognized in earnings		7,640			3,500
Settlements		(17,820	)		(25,000	)
Transfers		—			(25,000	)
Balance as of September 30, 2021	$	—		$	—

The following table presents a reconciliation of the Company’s financial asset and liability measured at fair value as of December 31, 2020 using significant unobservable inputs (Level 3), and the change in fair value (in thousands):

	Embedded Derivative		Convertible Security
Balance as of December 31, 2019	$	—	$	—
Initial fair value recognition		—		45,000
Change in fair value recognized in earnings		5,680		1,500
Balance as of December 31, 2020	$	5,680	$	46,500