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	12 Months Ended
Net Product Sales (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue Disclosure [Line Items]
Net product sales	$ 3,338,390	$ 2,689,478	$ 1,750,762
Activity of Sales Related Deductions [Roll Forward]
Balance	45,851	55,249	24,781	$ 24,601
Provision related to current period sales	278,304	193,190	111,855
Credits/payments	(287,702)	(162,722)	(111,675)
Rebates and Chargebacks
Activity of Sales Related Deductions [Roll Forward]
Balance	12,712	6,419	3,083	4,400
Provision related to current period sales	93,385	61,124	33,117
Credits/payments	(87,092)	(57,788)	(34,434)
Distribution Related Fees
Activity of Sales Related Deductions [Roll Forward]
Balance	29,465	48,313	21,166	19,663
Provision related to current period sales	154,477	122,466	77,160
Credits/payments	(173,325)	(95,319)	(75,657)
Other Sales Related Deductions
Activity of Sales Related Deductions [Roll Forward]
Balance	3,674	517	532	$ 538
Provision related to current period sales	30,442	9,600	1,578
Credits/payments	$ (27,285)	$ (9,615)	(1,584)
Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	99.00%	94.00%
EYLEA
Revenue Disclosure [Line Items]
Net product sales	$ 3,323,100	$ 2,676,000	1,736,400
ARCALYST
Revenue Disclosure [Line Items]
Net product sales	$ 15,300	$ 13,500	$ 14,400
Besse Medical \| Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	55.00%	67.00%	73.00%
McKesson Corporation \| Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	28.00%	26.00%	20.00%
Curascript SD \| Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage	16.00%
Curascript SD \| Maximum \| Customer concentration risk \| Gross Sales Revenue
Risks and Uncertainties [Abstract]
Concentration risk, percentage		10.00%	10.00%