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Number of development milestone payments the Company received

No definition available.

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Percentage of development cost for the territory outside the United States previously required to be paid for under the collaboration.

No definition available.

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Period Type:	duration

Percentage of development milestone payments Bayer HealthCare is obligated to reimburse the Company for payments that the Company makes to Sanofi related to the Company's acquisition of rights to antibodies targeting the PDGF family of receptors.

No definition available.

Name:	regn_Percentageofdevelopmentmilestonepaymentstobereimbursed
Namespace Prefix:	regn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage of global development cost to be paid by the collaboration partner under the collaboration

No definition available.

Name:	regn_Percentageofglobaldevelopmentcosttobepaidbythecollaborationpartnerunderthecollaboration
Namespace Prefix:	regn_
Data Type:	num:percentItemType
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Period Type:	duration

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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Data Type:	xbrli:stringItemType
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Amount of deferred revenue recognized for transactions arising during the current reporting period. Deferred revenue is a liability as of the balance sheet date related to a revenue producing activity for which revenue has not yet been recognized. Generally, an Entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SAB TOPIC 13.A.4(a).Q1)

-URI http://asc.fasb.org/extlink&oid=27012821&loc=d3e214044-122780

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 13

-Section A

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Cash received from collaborators during the current period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

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The amount of consideration recognized during the period for the milestone or milestones.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 605

-SubTopic 28

-Section 50

-Paragraph 2

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=51671726&loc=SL6892177-166501