For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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.

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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Total of the deductions in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs, representing receivables written off as uncollectible and portions of the reserves utilized, respectively.

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Net Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Net Product Sales (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Revenue Disclosure [Line Items]
Net product sales	$ 834,219	$ 657,819	$ 1,618,401	$ 1,202,392
Activity of Sales Related Deductions [Roll Forward]
Balance	40,846	45,458	40,846	45,458	$ 55,249	$ 24,781
Provision related to current period sales			127,956	83,682
Credits/payments			(142,359)	(63,005)
Rebates and Chargebacks
Activity of Sales Related Deductions [Roll Forward]
Balance	11,635	5,474	11,635	5,474	6,419	3,083
Provision related to current period sales			41,326	25,481
Credits/payments			(36,110)	(23,090)
Distribution Related Fees
Activity of Sales Related Deductions [Roll Forward]
Balance	28,135	39,480	28,135	39,480	48,313	21,166
Provision related to current period sales			74,289	54,747
Credits/payments			(94,467)	(36,433)
Other Sales Related Deductions
Activity of Sales Related Deductions [Roll Forward]
Balance	$ 1,076	$ 504	1,076	504	$ 517	$ 532
Provision related to current period sales			12,341	3,454
Credits/payments			$ (11,782)	$ (3,482)
Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	56.00%	69.00%	58.00%	69.00%
EYLEA
Revenue Disclosure [Line Items]
Net product sales	$ 830,900	$ 654,600	$ 1,611,800	$ 1,195,700
ARCALYST
Revenue Disclosure [Line Items]
Net product sales	$ 3,300	$ 3,200	$ 6,600	$ 6,700