Commercial Paper, Remaining Borrowing Capacity

No definition available.

Name:	celg_CommercialPaperRemainingBorrowingCapacity
Namespace Prefix:	celg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the debt instrument issuance price, expressed as a percentage of par value.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Increased maximum borrowing capacity, subject to certain conditions, under the credit facility.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Represents the maximum number of times the Company has the right to increase the amount of the Credit Facility subject to certain conditions.

+ References

No definition available.

+ Details

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- Definition

Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (d)
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-Name Accounting Standards Codification
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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unsecured short-term debt instrument issued by corporations which are 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. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3052-108585

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	na
Period Type:	instant

- 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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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
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+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount as of the balance sheet date of the unamortized adjustment to the carrying value of an interest-bearing hedged item made under an effective fair value hedge that is amortized upon discontinuation of the fair value hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 35
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=56949341&loc=d3e75592-113984

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Balance Type:	debit
Period Type:	instant

- Definition

Gross amount of debt extinguished.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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-Name Accounting Standards Codification
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 13
-Subparagraph 2, 3
-Article 9

+ Details

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Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_BusinessAcquisitionAxis=celg_QuanticelMember
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- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Debt (Narrative) (Details)	1 Months Ended	12 Months Ended
Debt (Narrative) (Details)	Aug. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) Time_Per_Annum	Apr. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)
Debt Instrument [Line Items]
Long-term debt, fair value		$ 14,299,000,000
Debt instrument, face amount	$ 8,000,000,000.000
Debt issuance cost		50,000,000
Accumulated OCI, loss position		21,600,000
Commercial paper carrying value		0		$ 99,600,000
Commercial Paper, remaining borrowing capacity		1,750,000,000
Quanticel
Debt Instrument [Line Items]
Amount of debt paid off		13,900,000
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,750,000,000.000	$ 1,500,000,000.000
Maximum number of credit facility increases \| Time_Per_Annum		1
Maximum borrowing capacity, subject to certain conditions		$ 2,000,000,000.000
Outstanding uncommitted facility		0		$ 0
Commercial Paper
Debt Instrument [Line Items]
Commercial paper debt outstanding		$ 0
2.125% senior notes due 2018
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,000,000,000.000
Interest rate (as a percent)	2.125%
Debt instrument, issuance price as percentage of par value	99.994%
Debt instrument, redemption price, percentage		1.20%
2.875% senior notes due 2020
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,500,000,000.000
Interest rate (as a percent)	2.875%
Debt instrument, issuance price as percentage of par value	99.819%
Debt instrument, redemption price, percentage		1.20%
3.550% senior notes due 2022
Debt Instrument [Line Items]
Debt instrument, face amount	$ 1,000,000,000.000
Interest rate (as a percent)	3.55%
Debt instrument, issuance price as percentage of par value	99.729%
Debt instrument, redemption price, percentage		1.25%
3.875% senior notes due 2025
Debt Instrument [Line Items]
Debt instrument, face amount	$ 2,500,000,000.000
Interest rate (as a percent)	3.875%
Debt instrument, issuance price as percentage of par value	99.034%
Debt instrument, redemption price, percentage		1.30%
5.000% senior notes due 2045
Debt Instrument [Line Items]
Debt instrument, face amount	$ 2,000,000,000.000
Interest rate (as a percent)	5.00%
Debt instrument, issuance price as percentage of par value	99.691%
Debt instrument, redemption price, percentage		1.35%
2015 Notes Redemption
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage		101.00%
2.450% senior notes due 2015
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500,000,000
Interest rate (as a percent)		2.45%
Senior Notes \| 2.125% senior notes due 2018
Debt Instrument [Line Items]
Interest rate (as a percent)		2.125%
Senior Notes \| 2.875% senior notes due 2020
Debt Instrument [Line Items]
Interest rate (as a percent)		2.875%
Senior Notes \| 3.550% senior notes due 2022
Debt Instrument [Line Items]
Interest rate (as a percent)		3.55%		3.55%
Senior Notes \| 3.875% senior notes due 2025
Debt Instrument [Line Items]
Interest rate (as a percent)		3.875%
Senior Notes \| 5.000% senior notes due 2045
Debt Instrument [Line Items]
Interest rate (as a percent)		5.00%
Derivative
Debt Instrument [Line Items]
Accumulated OCI, loss position		$ 68,100,000
Gain as a Result of Past Swap Contract Settlements
Debt Instrument [Line Items]
Deferred (gain) loss on discontinuation of fair value hedge		(33,100,000)
Gain Related to Settlement of Swap Contracts During Current Fiscal Year
Debt Instrument [Line Items]
Deferred (gain) loss on discontinuation of fair value hedge		$ (6,000,000)