Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Summary of financial assets with maturities of less than 90 days included within cash and cash equivalents

The following table summarizes our financial assets with maturities of less than 90 days from the date of purchase included in cash and cash equivalents in our condensed consolidated balance sheets:

(In millions)	As of March 31, 2022		As of December 31, 2021
Commercial paper	$	278.5	$	247.6
Overnight reverse repurchase agreements	13.9		200.0
Money market funds	585.0		901.6
Short-term debt securities	406.3		283.0
Total	$	1,283.7	$	1,632.2

Marketable debt and equity securities

The following tables summarize our marketable debt and equity securities, classified as available-for-sale:

	As of March 31, 2022
(In millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable debt securities
Corporate debt securities:
Current	$	1,126.7	$	0.1	$	(2.2)	$	1,124.6
Non-current	460.5		0.1		(5.8)		454.8
Government securities:
Current	878.7		1.0		(2.6)		877.1
Non-current	379.0		0.2		(3.6)		375.6
Mortgage and other asset backed securities:
Current	0.7		—		—		0.7
Non-current	173.4		—		(2.2)		171.2
Total marketable debt securities	$	3,019.0	$	1.4	$	(16.4)	$	3,004.0
Marketable equity securities
Marketable equity securities, current	$	33.9	$	—	$	—	$	33.9
Marketable equity securities, non-current	1,133.1		4.5		(311.2)		826.4
Total marketable equity securities	$	1,167.0	$	4.5	$	(311.2)	$	860.3

	As of December 31, 2021
(In millions)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value
Marketable debt securities
Corporate debt securities:
Current	$	723.6	$	0.1	$	(0.3)	$	723.4
Non-current	385.4		0.2		(0.8)		384.8
Government securities:
Current	817.0		—		(0.4)		816.6
Non-current	377.0		0.1		(1.0)		376.1
Mortgage and other asset backed securities:
Current	1.1		—		—		1.1
Non-current	131.8		—		(0.7)		131.1
Total marketable debt securities	$	2,435.9	$	0.4	$	(3.2)	$	2,433.1
Marketable equity securities
Marketable equity securities, current	$	33.9	$	9.9	$	—	$	43.8
Marketable equity securities, non-current	1,133.1		151.0		(279.4)		1,004.7
Total marketable equity securities	$	1,167.0	$	160.9	$	(279.4)	$	1,048.5

Summary of contractual maturities: available-for-sale securities

The estimated fair value and amortized cost of our marketable debt securities available-for-sale by contractual maturity are summarized as follows:

	As of March 31, 2022				As of December 31, 2021
(In millions)	Estimated Fair Value		Amortized Cost		Estimated Fair Value		Amortized Cost
Due in one year or less	$	2,002.4	$	2,006.0	$	1,541.1	$	1,541.7
Due after one year through five years	982.9		993.7		868.2		870.2
Due after five years	18.7		19.3		23.8		24.0
Total marketable debt securities	$	3,004.0	$	3,019.0	$	2,433.1	$	2,435.9

Proceeds from marketable debt securities

The proceeds from maturities and sales of marketable debt securities and resulting realized gains and losses are summarized as follows:

	For the Three Months Ended March 31,
(In millions)	2022		2021
Proceeds from maturities and sales	$	543.6	$	819.2
Realized gains	—		0.2
Realized losses	0.6		0.7