The compensation expense recognized during the period relating to the deferred compensation arrangement.

No definition available.

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Namespace Prefix:	celg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the number of performance cycles running concurrently.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Represents the payouts expressed as a percentage of participants' base salary under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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Namespace Prefix:	celg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the potential payout assuming maximum performance objectives are achieved under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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

- Definition

Represents the period over which the performance is measured to arrive at the performance-based incentives to be provided to the employees under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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- Definition

Represents the percentage of performance which is measured on the basis of non-GAAP net income in the last year of the three-year cycle under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	instant

- Definition

Represents the percentage of performance which is measured on the basis of non-GAAP revenue in the last year of the three-year cycle under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
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Period Type:	instant

- Definition

Represents the percentage of performance which is measured on the basis of relative shareholder return in the last year of the three-year cycle under the deferred compensation arrangement.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period of consecutive trading days used to calculate the average closing price of common stock to determine the stock-based performance awards.

+ References

No definition available.

+ Details

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Namespace Prefix:	celg_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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Balance Type:	na
Period Type:	duration

- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements payable within one year (or the operating cycle, if longer). Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 30

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6409875&loc=d3e20028-108363

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 710

-SubTopic 10

-Section 25

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=6409733&loc=d3e19512-108361

+ Details

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

- Details

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- Details

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- Details

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- Details

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Employee Benefit Plans (Long-Term Incentive Plan) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 performance_cycle	Dec. 31, 2013	Dec. 31, 2012
Long-Term Incentive Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Performance period	3 years
Number of separate three-year performance cycles	3
Estimated payout for the plan, current	$ 36.5
Consecutive trading days	30 days
Plan related expense	42.3	40.8	10.0
Long-Term Incentive Plan \| Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Payouts as percentage of the participant's salary	200.00%
Long-Term Incentive Plan \| Minimum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Payouts as percentage of the participant's salary	0.00%
2015 Long-Term Incentive Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Percentage of non-GAAP net income as component of performance measures of the plans	37.50%
Percentage of total non-GAAP revenue as component of performance measures of the plans	37.50%
Percentage of relative shareholder return as component of performance measures of the plans	25.00%
2015 Long-Term Incentive Plan \| Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Potential payout, assuming maximum objectives are achieved	22.6
2016 Long-Term Incentive Plan
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Percentage of non-GAAP net income as component of performance measures of the plans	37.50%
Percentage of total non-GAAP revenue as component of performance measures of the plans	37.50%
Percentage of relative shareholder return as component of performance measures of the plans	25.00%
2016 Long-Term Incentive Plan \| Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Potential payout, assuming maximum objectives are achieved	25.2
2017 Long-Term Incentive Plan \| Maximum
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Potential payout, assuming maximum objectives are achieved	$ 16.4