Fair Value Measurements - Financial Assets and Liabilities Subject to Fair Value Measurements (Details) - Recurring Basis - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Financial instruments carried at fair value (asset positions):
Cash equivalents	$ 1,216.6	$ 1,687.1
Prepaid expenses and other current assets, Foreign currency forward contracts	6.7	130.1
Other assets, Foreign currency forward contracts	9.4	12.4
Total financial assets	8,302.9	8,483.8
Financial instruments carried at fair value (liability positions):
Other current liabilities, Foreign currency forward contracts	(114.3)	0.0
Foreign currency forward contracts	(78.3)	0.0
Contingent consideration	(78.1)	(76.9)
Total financial liabilities	(270.7)	(76.9)
Level 1
Financial instruments carried at fair value (asset positions):
Cash equivalents	505.5	613.3
Prepaid expenses and other current assets, Foreign currency forward contracts	0.0	0.0
Other assets, Foreign currency forward contracts	0.0	0.0
Total financial assets	2,452.6	2,216.7
Financial instruments carried at fair value (liability positions):
Other current liabilities, Foreign currency forward contracts	0.0	0.0
Foreign currency forward contracts	0.0	0.0
Contingent consideration	0.0	0.0
Total financial liabilities	0.0	0.0
Level 2
Financial instruments carried at fair value (asset positions):
Cash equivalents	711.1	1,073.8
Prepaid expenses and other current assets, Foreign currency forward contracts	6.7	130.1
Other assets, Foreign currency forward contracts	9.4	12.4
Total financial assets	5,850.3	6,267.1
Financial instruments carried at fair value (liability positions):
Other current liabilities, Foreign currency forward contracts	(114.3)	0.0
Foreign currency forward contracts	(78.3)	0.0
Contingent consideration	0.0	0.0
Total financial liabilities	(192.6)	0.0
Level 3
Financial instruments carried at fair value (asset positions):
Cash equivalents	0.0	0.0
Prepaid expenses and other current assets, Foreign currency forward contracts	0.0	0.0
Other assets, Foreign currency forward contracts	0.0	0.0
Total financial assets	0.0	0.0
Financial instruments carried at fair value (liability positions):
Other current liabilities, Foreign currency forward contracts	0.0	0.0
Foreign currency forward contracts	0.0	0.0
Contingent consideration	(78.1)	(76.9)
Total financial liabilities	(78.1)	(76.9)
Corporate equity securities
Financial instruments carried at fair value (asset positions):
Marketable securities:	9.4	36.6
Corporate equity securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	9.4	36.6
Corporate equity securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Corporate equity securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
U.S. Treasury securities
Financial instruments carried at fair value (asset positions):
Marketable securities:	1,937.7	1,602.0
U.S. Treasury securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	1,937.7	1,566.8
U.S. Treasury securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	35.2
U.S. Treasury securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
U.S. government agency securities
Financial instruments carried at fair value (asset positions):
Marketable securities:	190.6	240.5
U.S. government agency securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
U.S. government agency securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	190.6	240.5
U.S. government agency securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Asset-backed securities
Financial instruments carried at fair value (asset positions):
Marketable securities:	1,361.0	1,244.2
Asset-backed securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Asset-backed securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	1,361.0	1,244.2
Asset-backed securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Certificates of deposit
Financial instruments carried at fair value (asset positions):
Marketable securities:	24.4	0.0
Certificates of deposit \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Certificates of deposit \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	24.4	0.0
Certificates of deposit \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Corporate debt securities
Financial instruments carried at fair value (asset positions):
Marketable securities:	3,538.4	3,525.9
Corporate debt securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Corporate debt securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	3,538.4	3,525.9
Corporate debt securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Commercial paper
Financial instruments carried at fair value (asset positions):
Marketable securities:	8.7	5.0
Commercial paper \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities:	0.0	0.0
Commercial paper \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities:	8.7	5.0
Commercial paper \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities:	$ 0.0	$ 0.0

Fair value portion of asset recognized for present right to economic benefit.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479581/805-30-50-1

+ Details

Name:	us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483444/210-20-55-10

+ Details

Name:	us-gaap_DerivativeAssetsCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

+ Details

Name:	us-gaap_DerivativeAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

+ Details

Name:	us-gaap_DerivativeLiabilitiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

+ Details

Name:	us-gaap_DerivativeLiabilitiesNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-28

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

+ Details

Name:	us-gaap_FinancialLiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in marketable security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(4))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

Name:	us-gaap_MarketableSecurities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommercialPaperMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: