Marketable Securities

12 Months Ended

Dec. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Marketable securities as of December 31, 2021 and 2020 consist of both available-for-sale debt securities of investment grade issuers (see below and Note 5) as well as equity securities of publicly traded companies (see Note 5).

The following tables summarize the Company's investments in available-for-sale debt securities:


(In millions)	Amortized		Unrealized				Fair
As of December 31, 2021	Cost Basis		Gains		Losses		Value
Corporate bonds	$	7,518.4	$	10.2	$	(40.9)	$	7,487.7
U.S. government and government agency obligations	109.0		0.3		(0.8)		108.5
Sovereign bonds	64.4		0.3		(0.3)		64.4
Commercial paper	439.7		—		(0.1)		439.6
Certificates of deposit	255.2		—		(0.1)		255.1
Asset-backed securities	42.0		—		(0.1)		41.9
	$	8,428.7	$	10.8	$	(42.3)	$	8,397.2

As of December 31, 2020
Corporate bonds	$	3,053.0	$	37.5	$	(0.2)	$	3,090.3
U.S. government and government agency obligations	127.6		1.3		—		128.9
Sovereign bonds	65.2		1.1		—		66.3
Commercial paper	276.0		0.1		—		276.1
Certificates of deposit	127.4		0.1		—		127.5
	$	3,649.2	$	40.1	$	(0.2)	$	3,689.1

The Company classifies its investments in available-for-sale debt securities based on their contractual maturity dates. The available-for-sale debt securities listed as of December 31, 2021 mature at various dates through November 2026. The fair values of available-for-sale debt securities by contractual maturity consist of the following:


	As of December 31,
(In millions)	2021		2020
Maturities within one year	$	2,809.1	$	1,393.3
Maturities after one year through five years	5,588.1		2,295.8
	$	8,397.2	$	3,689.1

The following table shows the fair value of the Company's available-for-sale debt securities that have unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous loss position.


	Less than 12 Months				12 Months or Greater		Total
(In millions) As of December 31, 2021	Fair Value		Unrealized Loss		Fair Value	Unrealized Loss	Fair Value		Unrealized Loss
Corporate bonds	$	5,889.3	$	(40.9)	—	—	$	5,889.3	$	(40.9)
U.S. government and government agency obligations	90.0		(0.8)		—	—	90.0		(0.8)
Sovereign bonds	37.0		(0.3)		—	—	37.0		(0.3)
Commercial paper	295.7		(0.1)		—	—	295.7		(0.1)
Certificates of deposit	169.4		(0.1)		—	—	169.4		(0.1)
Asset-backed securities	34.9		(0.1)		—	—	34.9		(0.1)
	$	6,516.3	$	(42.3)	—	—	$	6,516.3	$	(42.3)

As of December 31, 2020
Corporate bonds	$	364.5	$	(0.2)	—	—	$	364.5	$	(0.2)

Realized gains and losses on sales of marketable securities were not material for the year ended December 31, 2021. Realized gains on sales of marketable securities were $29.0 million and realized losses were not material for the year ended December 31, 2020. Realized gains on sales of marketable securities were not material and there were no realized losses for the year ended December 31, 2019.

With respect to marketable securities, for the years ended December 31, 2021, 2020, and 2019, amounts reclassified from Accumulated other comprehensive income (loss) into Other income (expense), net were related to realized gains and losses on sales of available-for-sale debt securities.