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.

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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, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Revenue Disclosure [Line Items]
Net product sales	$ 657,819	$ 418,022	$ 1,202,392	$ 780,400
Activity of Sales Related Deductions [Roll Forward]
Balance	45,458	25,082	45,458	25,082	$ 24,781	$ 24,601
Provision related to current period sales			83,682	51,841
Credits/payments			(63,005)	(51,360)
Rebates and Chargebacks
Activity of Sales Related Deductions [Roll Forward]
Balance	5,474	4,140	5,474	4,140	3,083	4,400
Provision related to current period sales			25,481	14,817
Credits/payments			(23,090)	(15,077)
Distribution Related Fees
Activity of Sales Related Deductions [Roll Forward]
Balance	39,480	20,420	39,480	20,420	21,166	19,663
Provision related to current period sales			54,747	36,206
Credits/payments			(36,433)	(35,449)
Other Sales Related Deductions
Activity of Sales Related Deductions [Roll Forward]
Balance	$ 504	$ 522	504	522	$ 532	$ 538
Provision related to current period sales			3,454	818
Credits/payments			$ (3,482)	$ (834)
Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	69.00%	73.00%	69.00%	76.00%
EYLEA
Revenue Disclosure [Line Items]
Net product sales	$ 654,600	$ 414,800	$ 1,195,700	$ 773,800
ARCALYST
Revenue Disclosure [Line Items]
Net product sales	$ 3,200	$ 3,200	$ 6,700	$ 6,600