Product Sales Schedule of Net Product Sales (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	$ 1,608,022	$ 1,470,116	$ 3,119,507	$ 2,789,107
Product
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	996,382	924,133	1,984,291	1,782,378
UNITED STATES | EYLEA
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	991,998	919,466	1,976,047	1,773,853
UNITED STATES | ARCALYST
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	4,384	4,667	8,244	8,525
UNITED STATES | Product
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenues	$ 996,382	$ 924,133	$ 1,984,291	$ 1,782,378