Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2021

Fair Value Disclosures [Abstract]

Summary of assets and liabilities recorded at fair value

The tables below present information about our assets and liabilities that are regularly measured and carried at fair value and indicate the level within the fair value hierarchy of the valuation techniques we utilized to determine such fair value:

	As of December 31, 2021
(In millions)	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	1,632.2	$	—	$	1,632.2	$	—
Marketable debt securities:
Corporate debt securities	1,108.2		—		1,108.2		—
Government securities	1,192.7		—		1,192.7		—
Mortgage and other asset backed securities	132.2		—		132.2		—
Marketable equity securities	1,048.5		181.7		866.8		—
Derivative contracts	80.9		—		80.9		—
Plan assets for deferred compensation	33.4		—		33.4		—
Total	$	5,228.1	$	181.7	$	5,046.4	$	—
Liabilities:
Derivative contracts	$	10.8	$	—	$	10.8	$	—
Contingent consideration obligations	209.1		—		—		209.1
Total	$	219.9	$	—	$	10.8	$	209.1

	As of December 31, 2020
(In millions)	Total		Quoted Prices in Active Markets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	$	626.9	$	—	$	626.9	$	—
Marketable debt securities:
Corporate debt securities	1,301.5		—		1,301.5		—
Government securities	627.1		—		627.1		—
Mortgage and other asset backed securities	122.4		—		122.4		—
Marketable equity securities	1,974.3		271.1		1,703.2		—
Derivative contracts	20.5		—		20.5		—
Plan assets for deferred compensation	28.2		—		28.2		—
Total	$	4,700.9	$	271.1	$	4,429.8	$	—
Liabilities:
Derivative contracts	$	217.2	$	—	$	217.2	$	—
Contingent consideration obligations	259.8		—		—		259.8
Total	$	477.0	$	—	$	217.2	$	259.8

Summary of significant unobservable inputs

The following tables summarize the significant unobservable inputs in the fair value measurement of our contingent consideration obligations as of December 31, 2021 and 2020:

	As of December 31, 2021
(In millions)	Fair Value	Valuation Technique	Unobservable Input	Range	Weighted Average
Liabilities:
Contingent consideration obligation	$209.1	Discounted cash flow	Discount rate	1.30%	1.30%
			Expected timing of achievement of development milestones	2023 to 2027	—

	As of December 31, 2020
(In millions)	Fair Value	Valuation Technique	Unobservable Input	Range	Weighted Average
Liabilities:
Contingent consideration obligation	$259.8	Discounted cash flow	Discount rate	0.60%	0.60%
			Expected timing of achievement of development milestones	2021 to 2025	—

Summary of fair and carrying value of debt instruments

The fair values of our debt instruments, which are Level 2 liabilities, are summarized as follows:

	As of December 31,
(In millions)	2021		2020
3.625% Senior Notes due September 15, 2022	$	1,020.0	$	1,054.1
4.050% Senior Notes due September 15, 2025	1,895.2		2,003.1
2.250% Senior Notes due May 1, 2030	1,475.9		1,557.2
5.200% Senior Notes due September 15, 2045(1)	1,463.0		2,365.1
3.150% Senior Notes due May 1, 2050	1,457.7		1,536.4
3.250% Senior Notes due February 15, 2051(1)	692.9		—
Total	$	8,004.7	$	8,515.9

(1) In February 2021 we completed a private offer to exchange (Exchange Offer) our tendered 5.200% Senior Notes due September 15, 2045 (2045 Senior Notes), whereby approximately $624.6 million of our 2045 Senior Notes were exchanged for approximately $700.7 million of a new series of 3.250% Senior Notes due February 15, 2051 (2051 Senior Notes). For additional information on our Exchange Offer, please read Note 12, Indebtedness, to these consolidated financial statements.

Fair value of contingent consideration obligations

The following table provides a roll forward of the fair values of our contingent consideration obligations, which includes Level 3 measurements:

	As of December 31,
(In millions)	2021		2020
Fair value, beginning of year	$	259.8	$	346.1
Changes in fair value	(50.7)		(86.3)
Fair value, end of year	$	209.1	$	259.8