Collaborative Agreements (Schedule Of Activity Related To Collaboration) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Collaborative Agreements [Line Items]
Collaborative profit-sharing	$ 0	$ 60,652	$ 0	$ 120,503
Revenues under collaborative agreements			3,750	3,750
Royalty Revenue Member | Lilly [Member]
Collaborative Agreements [Line Items]
Royalty Revenue	957	1,401	2,083	1,401
Gross Margin Cost Sharing [Member] | Lilly [Member]
Collaborative Agreements [Line Items]
Collaborative profit-sharing	0	60,652	0	120,503
Development Expense Cost Sharing Payments Received From Lilly For Byetta And Bydureon Development Expense [Member] | Lilly [Member]
Collaborative Agreements [Line Items]
Reduction of research and development expense	0	17,842	0	35,188
Cost Sharing Payments Due To Lilly For Shared Sales Force Expenses Marketing Expenses And Other Commercial Or Operational Support [Member] | Lilly [Member]
Collaborative Agreements [Line Items]
Reduction of selling, general and administrative expense	0	2,300	0	5,637
Amortization Of Up Front Payments [Member] | Takeda Agreement [Member]
Collaborative Agreements [Line Items]
Revenues under collaborative agreements	1,875	1,875	3,750	3,750
Cost Sharing Payments Due From Takeda For Shared Development Expenses Member | Takeda Agreement [Member]
Collaborative Agreements [Line Items]
Reduction of research and development expense	$ 571	$ 1,971	$ 1,329	$ 6,989