Fair Value Measurements - Financial Assets and Liabilities Subject to Fair Value Measurements (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financial instruments carried at fair value (liability positions):
Long-term contingent consideration	$ (185,700)	$ (189,600)
Recurring Basis
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	7,039	0
Derivative asset noncurrent, foreign currency forward contracts	1,944	0
Total financial assets	4,518,924	3,811,763
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	(28,743)	(59,184)
Long-term contingent consideration	(185,700)	(189,600)
Derivative liability noncurrent, foreign currency forward contracts	(433)	(4,283)
Total financial liabilities	(214,876)	(253,067)
Recurring Basis \| Level 1
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	0	0
Derivative asset noncurrent, foreign currency forward contracts	0	0
Total financial assets	4,096,151	3,236,766
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	0	0
Long-term contingent consideration	0	0
Derivative liability noncurrent, foreign currency forward contracts	0	0
Total financial liabilities	0	0
Recurring Basis \| Level 2
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	7,039	0
Derivative asset noncurrent, foreign currency forward contracts	1,944	0
Total financial assets	422,773	574,997
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	(28,743)	(59,184)
Long-term contingent consideration	0	0
Derivative liability noncurrent, foreign currency forward contracts	(433)	(4,283)
Total financial liabilities	(29,176)	(63,467)
Recurring Basis \| Level 3
Financial instruments carried at fair value (asset positions):
Derivative asset current, foreign currency forward contracts	0	0
Derivative asset noncurrent, foreign currency forward contracts	0	0
Total financial assets	0	0
Financial instruments carried at fair value (liability positions):
Derivative liability current, foreign currency forward contracts	0	0
Long-term contingent consideration	(185,700)	(189,600)
Derivative liability noncurrent, foreign currency forward contracts	0	0
Total financial liabilities	(185,700)	(189,600)
Recurring Basis \| Money market funds
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	3,890,303	3,141,053
Recurring Basis \| Money market funds \| Level 1
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	3,890,303	3,141,053
Recurring Basis \| Money market funds \| Level 2
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Recurring Basis \| Money market funds \| Level 3
Financial instruments carried at fair value (asset positions):
Cash and cash equivalents	0	0
Recurring Basis \| Corporate equity securities
Financial instruments carried at fair value (asset positions):
Marketable securities	143,486	195,781
Recurring Basis \| Corporate equity securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	143,486	15,650
Recurring Basis \| Corporate equity securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	0	180,131
Recurring Basis \| Corporate equity securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Government-sponsored enterprise securities
Financial instruments carried at fair value (asset positions):
Marketable securities	62,362	80,063
Recurring Basis \| Government-sponsored enterprise securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	62,362	80,063
Recurring Basis \| Government-sponsored enterprise securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Government-sponsored enterprise securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Corporate debt securities
Financial instruments carried at fair value (asset positions):
Marketable securities	155,716	231,598
Recurring Basis \| Corporate debt securities \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Corporate debt securities \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	155,716	231,598
Recurring Basis \| Corporate debt securities \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Commercial paper
Financial instruments carried at fair value (asset positions):
Marketable securities	258,074	163,268
Recurring Basis \| Commercial paper \| Level 1
Financial instruments carried at fair value (asset positions):
Marketable securities	0	0
Recurring Basis \| Commercial paper \| Level 2
Financial instruments carried at fair value (asset positions):
Marketable securities	258,074	163,268
Recurring Basis \| Commercial paper \| Level 3
Financial instruments carried at fair value (asset positions):
Marketable securities	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 35
-Paragraph 1
-Subparagraph b
-URI http://asc.fasb.org/extlink&oid=116859824&loc=d3e6819-128478

+ 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

No definition available.

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ 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

No definition available.

+ 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

+ 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_MoneyMarketFundsMember
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_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
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: