Fair value measurements (Tables)

9 Months Ended

Sep. 30, 2021

Fair Value Disclosures [Abstract]

Schedule of assets and liabilities measured at fair value on a recurring basis

The following table sets forth the assets that we measure at fair value on a recurring basis by level in the fair value hierarchy (in thousands). There were no liabilities measured at fair value on a recurring basis as of September 30, 2021, and December 31, 2020. In addition, there were no transfers of assets measured at fair value on a recurring basis to or from Level 3 in the fair value hierarchy during the nine months ended September 30, 2021.

			Fair Value Measurement Using
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Investments in publicly traded companies:
As of September 30, 2021	$	657,331	$	657,331	$	—	$	—
As of December 31, 2020	$	559,830	$	559,830	$	—	$	—

Schedule of assets and liabilities measure at fair value on a nonrecurring basis

The following table sets forth the assets measured at fair value on a nonrecurring basis by level within the fair value hierarchy as of September 30, 2021 (in thousands). These investments were measured at various times during the period from January 1, 2018, to September 30, 2021.

			Fair Value Measurement Using
Description	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)
Investments in privately held entities that do not report NAV
As of September 30, 2021	$	135,524	$	—	$	129,468	(1)	$	6,056	(2)
As of December 31, 2020	$	157,871	$	—	$	144,404		$	13,467

(1)This balance represents the total carrying amount of our equity investments in privately held entities with observable price changes, included in our total investments balance of $2.0 billion in our consolidated balance sheets as of September 30, 2021. For more information, refer to Note 7 – “Investments” to our unaudited consolidated financial statements.

(2)This amount is included in the $349.1 million balance of investments in privately held entities without observable price changes disclosed in Note 7 – “Investments” to our unaudited consolidated financial statements and represents the carrying amount of investments in privately held entities that do not report NAV for which impairments have been recognized in accordance with the measurement alternative guidance described within the “Investments” section in Note 2 – “Summary of significant accounting policies” to our unaudited consolidated financial statements.

As of September 30, 2021, and December 31, 2020, the book and estimated fair values of our secured notes payable, unsecured senior notes payable, and amounts outstanding under our unsecured senior line of credit and commercial paper program, including the level within the fair value hierarchy for which the estimates were derived, were as follows (in thousands):

	September 30, 2021
	Book Value		Fair Value Hierarchy						Estimated Fair Value
			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Liabilities:
Secured notes payable	$	198,758	$	—	$	208,553	$	—	$	208,553
Unsecured senior notes payable	$	8,314,851	$	—	$	9,031,303	$	—	$	9,031,303
Unsecured senior line of credit	$	—	$	—	$	—	$	—	$	—
Commercial paper program	$	749,978	$	—	$	749,986	$	—	$	749,986

	December 31, 2020
	Book Value		Fair Value Hierarchy						Estimated Fair Value
			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Liabilities:
Secured notes payable	$	230,925	$	—	$	249,782	$	—	$	249,782
Unsecured senior notes payable	$	7,232,370	$	—	$	8,447,845	$	—	$	8,447,845
Unsecured senior line of credit	$	—	$	—	$	—	$	—	$	—
Commercial paper program	$	99,991	$	—	$	99,998	$	—	$	99,998