Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Available-for-sale Debt Securities

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

(In millions)	Amortized		Unrealized				Fair
As of March 31, 2022	Cost Basis		Gains		Losses		Value
Corporate bonds	$	8,422.3	$	1.3	$	(207.4)	$	8,216.2
U.S. government and government agency obligations	385.8		—		(3.9)		381.9
Sovereign bonds	55.2		—		(1.5)		53.7
Commercial paper	712.7		—		(1.3)		711.4
Certificates of deposit	344.2		—		(0.9)		343.3
Asset-backed securities	44.9		—		(1.2)		43.7
	$	9,965.1	$	1.3	$	(216.2)	$	9,750.2
As of December 31, 2021
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

Marketable Securities, Based on Contractual Maturity Dates

The fair values of available-for-sale debt securities by contractual maturity consist of the following:

	March 31,		December 31,
(In millions)	2022		2021
Maturities within one year	$	3,704.9	$	2,809.1
Maturities after one year through five years	6,045.3		5,588.1
	$	9,750.2	$	8,397.2

Fair Value and Unrealized Losses of Marketable Securities

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 March 31, 2022	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Corporate bonds	$	7,269.3	$	(194.2)	$	212.9	$	(13.2)	$	7,482.2	$	(207.4)
U.S. government and government agency obligations	326.2		(3.8)		1.2		(0.1)		327.4		(3.9)
Sovereign bonds	44.7		(1.5)		—		—		44.7		(1.5)
Commercial paper	666.5		(1.3)		—		—		666.5		(1.3)
Certificates of deposit	324.5		(0.9)		—		—		324.5		(0.9)
Asset-backed securities	43.7		(1.2)		—		—		43.7		(1.2)
	$	8,674.9	$	(202.9)	$	214.1	$	(13.3)	$	8,889.0	$	(216.2)
As of December 31, 2021
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)