Collaboration Agreements (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Collaboration Agreements [Line Items]
Research and Development Expense	$ 287,379,000	$ 180,299,000
Number of sales milestone payments the Company received	2
Number of Payments the Company made	2
Revenue from Related Parties	130,508,000	99,273,000
Other Collaboration Revenue	125,312,000	14,907,000
Deferred Revenue, Additions	25,500,000
Levels of twelve month sales at which sales milestone payments were received	500,000,000
Levels of twelve month sales at which sales milestone payments were received - 5th tier	600,000,000
Period for Achieving Sales Target for Milestone Payment, Rolling Basis	12 months
levels of twelve month sales at which sales milestone payments maybe received - 200 million	200,000,000
levels of twelve months sales at which sales milestone payments maybe received - 1 billion	1,000,000,000
Amount of non-refundable payment received for collaboration agreement	25,500,000
sales achievement - 500 million
Collaboration Agreements [Line Items]
Revenue Recognition, Milestone Method, Revenue Recognized	15,000,000
sales achievement - 600 million
Collaboration Agreements [Line Items]
Revenue Recognition, Milestone Method, Revenue Recognized	15,000,000
sales achievement - 1 billion
Collaboration Agreements [Line Items]
Maximum amount of milestone payments that may be received if certain sales are achieved	60,000,000
sales achievement - 200 million
Collaboration Agreements [Line Items]
Maximum amount of sales milestone payments if total sales achieve specific levels	30,000,000
ZALTRAP Agreement
Collaboration Agreements [Line Items]
Net profit (loss) from commercialization of products under collaboration agreement	(3,212,000)	(7,789,000)
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned	1,092,000	2,089,000
Contracts Revenue	2,177,000	1,858,000
Revenue from Related Parties	57,000	(3,842,000)
Antibody Collaboration
Collaboration Agreements [Line Items]
Percentage of Trial Costs borne by collaborating party	80.00%
Percentage of Trial Costs borne by entity	20.00%
Research and Development Expense	23,800,000
Other Research and Development Expense	5,000,000
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned	126,822,000	99,623,000
Contracts Revenue	3,629,000	3,492,000
Revenue from Related Parties	130,451,000	103,115,000
Milestone Payment	30,000,000
Collaboration Agreement with Bayer HealthCare
Collaboration Agreements [Line Items]
Opt-in payment	20,000,000
Amount of milestone payment that may be received relating to marketing approval	20,000,000
Revenue Recognition, Milestone Method, Revenue Recognized	2,500,000
Future development milestone payments	15,000,000
Deferred Revenue, Additions	2,500,000
Percentage of global development cost to be paid by the collaboration partner under the collaboration	25.00%
Percentage of development cost for the territory outside the United States to be paid for under the collaboration	50.00%
Percentage of development milestone payments to be reimbursed	50.00%
Number of development milestone payments the Company received	2
EYLEA
Collaboration Agreements [Line Items]
Net profit (loss) from commercialization of products under collaboration agreement	61,159,000	6,362,000
Revenue Recognition, Milestone Method, Revenue Recognized	30,000,000	0
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned	20,347,000	5,888,000
Contracts Revenue	10,932,000	2,657,000
Other Collaboration Revenue	122,438,000	14,907,000
PDGFR-beta
Collaboration Agreements [Line Items]
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned	513,000	0
Contracts Revenue	2,361,000	0
Other Collaboration Revenue	2,874,000	0
BRVO
Collaboration Agreements [Line Items]
Research and Development Arrangement, Contract to Perform for Others, Compensation Earned	$ 15,700,000