Loss Contingency, Domiciles of Investigation

No definition available.

Name:	celg_LossContingencyDomicilesofInvestigation
Namespace Prefix:	celg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of Stockholders

+ References

No definition available.

+ Details

Name:	celg_NumberofStockholders
Namespace Prefix:	celg_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of royalty received from sale of products.

+ References

No definition available.

+ Details

Name:	celg_RoyaltyRate
Namespace Prefix:	celg_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- 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

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

- Definition

Number of claims dismissed.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyClaimsDismissedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

+ Details

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of plaintiffs that have filed claims pertaining to a loss contingency.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyNumberOfPlaintiffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of another entity's patents that the entity has allegedly infringed.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyPatentsAllegedlyInfringedNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated maximum amount of possible loss from the contingency.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 9

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349

+ Details

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

- Definition

The estimated minimum amount of possible loss from the contingency.

+ References

+ Details

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

- Details

Name:	us-gaap_LitigationCaseAxis=celg_AndrulisPharmaceuticalsCorporationPatentInfringementMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_LitigationCaseAxis=celg_LitigationRelatedtoSalesofTHALOMIDandREVLIMIDMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationCaseAxis=celg_ChildrensMedicalCenterCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=celg_RevlimidRoyaltyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=celg_PomalystRoyaltyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LitigationCaseAxis=celg_NatcoArrowandWatsonMember
Namespace Prefix:
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Legal Proceedings (Narrative) (Details)					1 Months Ended	12 Months Ended
Legal Proceedings (Narrative) (Details)	Apr. 11, 2014 lawsuit	Apr. 03, 2014 Patents	Oct. 02, 2013 lawsuit	Jun. 07, 2013	Feb. 28, 2014 lawsuit plaintiff	Dec. 31, 2012	Sep. 30, 2015 USD ($)	Jul. 31, 2014 number_of_stockholders
Loss Contingencies [Line Items]
Domicile of litigation						2
Number of Stockholders \| number_of_stockholders								2
Andrulis Pharmaceuticals Corporation Patent Infringement
Loss Contingencies [Line Items]
Claims dismissed	2
Patents allegedly infringed	4		1
Litigation Related to Sales of THALOMID and REVLIMID
Loss Contingencies [Line Items]
Number of civil qui tam actions					3
Number of plaintiffs \| plaintiff					3
Children's Medical Center Corporation
Loss Contingencies [Line Items]
Range of possible loss, minimum \| $							$ 0
Range of possible loss, maximum \| $							$ 126,300,000.0
Children's Medical Center Corporation \| revlimid royalty
Loss Contingencies [Line Items]
Royalty rate				0.01
Children's Medical Center Corporation \| pomalyst royalty
Loss Contingencies [Line Items]
Royalty rate				0.025
Pending Litigation \| Natco, Arrow and Watson
Loss Contingencies [Line Items]
Patents allegedly infringed \| Patents		5