| Revenue from External Customers by Products and Services [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended
September 30, | Net Product Sales in the United States | | 2017 | | 2016 | | 2017 | | 2016 | EYLEA® | | $ | 953,279 |
| | $ | 853,588 |
| | $ | 2,727,132 |
| | $ | 2,465,369 |
| ARCALYST® | | 4,088 |
| | 3,880 |
| | 12,613 |
| | 10,500 |
| Net Product Sales | | $ | 957,367 |
| | $ | 857,468 |
| | $ | 2,739,745 |
| | $ | 2,475,869 |
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| 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 each of the three and nine months ended September 30, 2017 and 2016. Sales to each of these customers as a percentage of the Company's total gross product revenue are as follows: | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended
September 30, | | | 2017 | | 2016 | | 2017 | | 2016 | Besse Medical, a subsidiary of AmerisourceBergen Corporation | | 51 | % | | 54 | % | | 51 | % | | 56 | % | McKesson Corporation | | 29 | % | | 28 | % | | 29 | % | | 28 | % | Curascript SD Specialty Distribution, a subsidiary of Express Scripts | | 19 | % | | 17 | % | | 19 | % | | 15 | % |
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| Sales Related Deductions Activity |
The following table summarizes the provisions and credits/payments for these sales-related deductions during the nine months ended September 30, 2017 and 2016. | | | | | | | | | | | | | | | | | | Rebates & Chargebacks | | Distribution- Related Fees | | Other Sales- Related Deductions | | Total | Balance as of December 31, 2016 | $ | 12,712 |
| | $ | 29,465 |
| | $ | 3,674 |
| | $ | 45,851 |
| Provisions | 121,599 |
| | 140,860 |
| | 33,518 |
| | 295,977 |
| Credits/payments | (108,811 | ) | | (136,272 | ) | | (21,444 | ) | | (266,527 | ) | Balance as of September 30, 2017 | $ | 25,500 |
| | $ | 34,053 |
| | $ | 15,748 |
| | $ | 75,301 |
| | | | | | | | | Balance as of December 31, 2015 | $ | 6,419 |
| | $ | 48,313 |
| | $ | 517 |
| | $ | 55,249 |
| Provisions | 63,510 |
| | 113,755 |
| | 22,812 |
| | 200,077 |
| Credits/payments | (62,503 | ) | | (135,483 | ) | | (19,587 | ) | | (217,573 | ) | Balance as of September 30, 2016 | $ | 7,426 |
| | $ | 26,585 |
| | $ | 3,742 |
| | $ | 37,753 |
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