Employee Benefit Plans	12 Months Ended
Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans We sponsor an employee savings and retirement plan, which qualifies under Section 401(k) of the Internal Revenue Code, as amended (the Code) for our U.S. employees. Our contributions to the U.S. savings plan are discretionary and have historically been made in the form of our common stock (See Note 12). Such contributions are based on specified percentages of employee contributions up to 6% of eligible compensation or a maximum permitted by law. Total expense for contributions to the U.S. savings plans were $35.1 million, $40.7 million and $32.6 million in 2015, 2014 and 2013, respectively. We also sponsor defined contribution plans in certain foreign locations. Participation in these plans is subject to the local laws that are in effect for each country and may include statutorily imposed minimum contributions. We also maintain defined benefit plans in certain foreign locations for which the obligations and the net periodic pension costs were determined to be immaterial at December 31, 2015. In 2000, our Board of Directors approved a deferred compensation plan. The plan was frozen effective as of December 31, 2004, and no additional contributions or deferrals can be made to that plan. Accrued benefits under the frozen plan will continue to be governed by the terms under the tax laws in effect prior to the enactment of American Jobs Creation Act of 2004, Section 409A (Section 409A). In February 2005, our Board of Directors adopted the Celgene Corporation 2005 Deferred Compensation Plan, effective as of January 1, 2005, and amended the plan in February 2008. This plan operates as our ongoing deferred compensation plan and is intended to comply with Section 409A. Eligible participants, which include certain top-level executives as specified by the plan, can elect to defer up to an amended 90% of the participant's base salary, 100% of cash bonuses and equity compensation allowed under Section 409A. Company contributions to the deferred compensation plan represent a match to certain participants' deferrals up to a specified percentage, which currently ranges from 10% to 20%, depending on the employee's position as specified in the plan, of the participant's base salary. We recorded expenses of $0.3 million, $0.3 million and $0.6 million related to the deferred compensation plans in 2015, 2014 and 2013, respectively. The Company's matches are fully vested upon contribution. All other Company contributions to the plan do not vest until the specified requirements are met. At December 31, 2015 and 2014, we had a deferred compensation liability included in other non-current liabilities in the Consolidated Balance Sheets of approximately $104.5 million and $91.0 million, respectively, which included the participant's elected deferral of salaries and bonuses, the Company's matching contribution and earnings on deferred amounts as of that date. The plan provides various alternatives for the measurement of earnings on the amounts participants defer under the plan. The measurement alternatives are based on returns of a variety of funds that offer plan participants the option to spread their risk across a diverse group of investments. In 2003, we established a Long-Term Incentive Plan (LTIP) designed to provide key officers and executives with performance-based incentive opportunities contingent upon achievement of pre-established corporate performance objectives covering a three-year period. We currently have three separate three-year performance cycles running concurrently ending December 31, 2016, 2017 and 2018. Performance measures for each of the performance cycles are based on the following components: 37.5% on non-GAAP earnings per share (as defined in the LTIP); 37.5% on total non-GAAP revenue (as defined in the LTIP); and 25% on relative total shareholder return, which is a measurement of our stock price performance during the applicable three-year period compared with a group of other companies in the biopharmaceutical industry. Threshold, target and maximum cash payout levels under the three current LTIP performance cycles are calculated as a percentage between 0% to 200% of each participant’s base salary at the time the LTIP was approved by the Compensation Committee. Such awards are payable in cash or common stock or a mixture of cash and common stock, which will be determined by the Compensation Committee at the time of award delivery. Share-based payout levels are calculated using the cash-based threshold, target and maximum levels, divided by the average closing price of Celgene stock for the 30 trading days prior to the commencement of each performance cycle. Therefore, final share-based award values are reflective of the stock price at the end of the measurement period. The Compensation Committee may determine that payments made in common stock are restricted from trading for a period of time. The estimated payout value for the concluded 2015 Plan is $17.4 million, which is included in accrued expenses at December 31, 2015, and the maximum potential cash-based payout, assuming maximum objectives are achieved for the 2016, 2017 and 2018 Plans are $25.2 million, $16.4 million and $16.3 million respectively. The reduction in the maximum potential cash-based payout for the 2017 Plan reflects a shift in the mix of compensation components for certain senior executives, including performance-based equity compensation in lieu of LTIP participation. We accrue the long-term incentive liability over each three-year cycle. Prior to the end of a three-year cycle, the accrual is based on an estimate of our level of achievement during the cycle. Upon a change in control, participants will be entitled to an immediate payment equal to their target award or, if higher, an award based on actual performance through the date of the change in control. For the years ended December 31, 2015, 2014 and 2013, we recognized expense related to the LTIP of $24.9 million, $42.3 million and $40.8 million, respectively.

Employee Benefit Plans

We sponsor an employee savings and retirement plan, which qualifies under Section 401(k) of the Internal Revenue Code, as amended (the Code) for our U.S. employees. Our contributions to the U.S. savings plan are discretionary and have historically been made in the form of our common stock (See Note 12). Such contributions are based on specified percentages of employee contributions up to 6% of eligible compensation or a maximum permitted by law. Total expense for contributions to the U.S. savings plans were $35.1 million, $40.7 million and $32.6 million in 2015, 2014 and 2013, respectively.

We also sponsor defined contribution plans in certain foreign locations. Participation in these plans is subject to the local laws that are in effect for each country and may include statutorily imposed minimum contributions. We also maintain defined benefit plans in certain foreign locations for which the obligations and the net periodic pension costs were determined to be immaterial at December 31, 2015.

In 2000, our Board of Directors approved a deferred compensation plan. The plan was frozen effective as of December 31, 2004, and no additional contributions or deferrals can be made to that plan. Accrued benefits under the frozen plan will continue to be governed by the terms under the tax laws in effect prior to the enactment of American Jobs Creation Act of 2004, Section 409A (Section 409A).

In February 2005, our Board of Directors adopted the Celgene Corporation 2005 Deferred Compensation Plan, effective as of January 1, 2005, and amended the plan in February 2008. This plan operates as our ongoing deferred compensation plan and is intended to comply with Section 409A. Eligible participants, which include certain top-level executives as specified by the plan, can elect to defer up to an amended 90% of the participant's base salary, 100% of cash bonuses and equity compensation allowed under Section 409A. Company contributions to the deferred compensation plan represent a match to certain participants' deferrals up to a specified percentage, which currently ranges from 10% to 20%, depending on the employee's position as specified in the plan, of the participant's base salary. We recorded expenses of $0.3 million, $0.3 million and $0.6 million related to the deferred compensation plans in 2015, 2014 and 2013, respectively. The Company's matches are fully vested upon contribution. All other Company contributions to the plan do not vest until the specified requirements are met. At December 31, 2015 and 2014, we had a deferred compensation liability included in other non-current liabilities in the Consolidated Balance Sheets of approximately $104.5 million and $91.0 million, respectively, which included the participant's elected deferral of salaries and bonuses, the Company's matching contribution and earnings on deferred amounts as of that date. The plan provides various alternatives for the measurement of earnings on the amounts participants defer under the plan. The measurement alternatives are based on returns of a variety of funds that offer plan participants the option to spread their risk across a diverse group of investments.

In 2003, we established a Long-Term Incentive Plan (LTIP) designed to provide key officers and executives with performance-based incentive opportunities contingent upon achievement of pre-established corporate performance objectives covering a three-year period. We currently have three separate three-year performance cycles running concurrently ending December 31, 2016, 2017 and 2018. Performance measures for each of the performance cycles are based on the following components: 37.5% on non-GAAP earnings per share (as defined in the LTIP); 37.5% on total non-GAAP revenue (as defined in the LTIP); and 25% on relative total shareholder return, which is a measurement of our stock price performance during the applicable three-year period compared with a group of other companies in the biopharmaceutical industry.

Threshold, target and maximum cash payout levels under the three current LTIP performance cycles are calculated as a percentage between 0% to 200% of each participant’s base salary at the time the LTIP was approved by the Compensation Committee. Such awards are payable in cash or common stock or a mixture of cash and common stock, which will be determined by the Compensation Committee at the time of award delivery. Share-based payout levels are calculated using the cash-based threshold, target and maximum levels, divided by the average closing price of Celgene stock for the 30 trading days prior to the commencement of each performance cycle. Therefore, final share-based award values are reflective of the stock price at the end of the measurement period. The Compensation Committee may determine that payments made in common stock are restricted from trading for a period of time. The estimated payout value for the concluded 2015 Plan is $17.4 million, which is included in accrued expenses at December 31, 2015, and the maximum potential cash-based payout, assuming maximum objectives are achieved for the 2016, 2017 and 2018 Plans are $25.2 million, $16.4 million and $16.3 million respectively. The reduction in the maximum potential cash-based payout for the 2017 Plan reflects a shift in the mix of compensation components for certain senior executives, including performance-based equity compensation in lieu of LTIP participation. We accrue the long-term incentive liability over each three-year cycle. Prior to the end of a three-year cycle, the accrual is based on an estimate of our level of achievement during the cycle. Upon a change in control, participants will be entitled to an immediate payment equal to their target award or, if higher, an award based on actual performance through the date of the change in control. For the years ended December 31, 2015, 2014 and 2013, we recognized expense related to the LTIP of $24.9 million, $42.3 million and $40.8 million, respectively.