Aggregate future development milestone payments the Company is eligible to receive.

No definition available.

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- Definition

The aggregate amount of additional payments the Company is entitled to receive upon the achievement of specified annual net sales amounts.

+ References

No definition available.

+ Details

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- Definition

Revenue Recognition, Development Milestone Achieved

+ References

No definition available.

+ Details

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- Definition

Up-front payment received upon the execution of a collaboration agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	regn_
Data Type:	xbrli:monetaryItemType
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- Definition

Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from contract modification which increases (decreases) right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130551-203045

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

+ Details

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Balance Type:	credit
Period Type:	instant

- Details

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- Details

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Collaboration, License, and Other Agreements - Teva Narrative (Details) - Teva - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2018	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Up-front payment received			$ 250,000,000.0
Development milestone achieved		$ 60,000,000.0
Aggregate future development milestone payments the Company is eligible to receive	$ 340,000,000.0
Collaborative arrangement, additional eligible aggregate payments	1,890,000,000
Remaining performance obligation	155,900,000
Other Operating Income (Expense)
Disaggregation of Revenue [Line Items]
Cumulative catch-up adjustment to revenue, modification of contract	$ (25,600,000)