Net Product Sales (Tables)

3 Months Ended

Mar. 31, 2018

Revenue from External Customer [Line Items]

Revenue from External Customers by Products and Services [Table Text Block]

Net product sales consist of the following:

	Three Months Ended March 31,
Net Product Sales in the United States	2018		2017
EYLEA®	$	984,049	$	854,387
ARCALYST®	3,860		3,858
	$	987,909	$	858,245

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

The Company had product sales to certain customers that accounted for more than 10% of total gross product revenue for the three months ended March 31, 2018 and 2017. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows:

	Three Months Ended March 31,
	2018		2017
Besse Medical, a subsidiary of AmerisourceBergen Corporation	55	%	53	%
McKesson Corporation	40	%	27	%
Curascript SD Specialty Distribution, a subsidiary of Express Scripts	**		19	%
** For the three months ended March 31, 2018, sales to Curascript SD Specialty Distribution represented less than 10% of total gross product revenue.

Sales Related Deductions Activity

The following table summarizes the provisions, and credits/payments, for these sales-related deductions during the three months ended March 31, 2018 and 2017.

	Rebates & Chargebacks			Distribution- Related Fees			Other Sales- Related Deductions			Total
Balance as of December 31, 2017	$	29,840		$	34,142		$	21,320		$	85,302
Provisions	48,495			51,716			11,170			111,381
Credits/payments	(30,674		)	(42,025		)	(14,665		)	(87,364		)
Balance as of March 31, 2018	$	47,661		$	43,833		$	17,825		$	109,319
Balance as of December 31, 2016	$	12,712		$	29,465		$	3,674		$	45,851
Provisions	38,908			41,175			9,520			89,603
Credits/payments	(28,502		)	(42,287		)	(8,632		)	(79,421		)
Balance as of March 31, 2017	$	23,118		$	28,353		$	4,562		$	56,033