Contingencies (Details) (Product Liability Litigation [Member])	3 Months Ended
	Mar. 31, 2013
Byetta [Member]
Loss Contingency, Number of Lawsuits	160
Loss Contingency, Number of Plaintiffs	545
Loss Contingency, Number of Claimants	460
Diethylstilbestrol (DES) [Member]
Loss Contingency, Number of Lawsuits	80
Loss Contingency, Number of Claimants	80
Prozac [Member]
Loss Contingency, Number of Lawsuits	7
Loss Contingency, Number of Claimants	340
Damages from Product, Breast Cancer [Member] | Diethylstilbestrol (DES) [Member]
Loss Contingency, Number of Claimants	75
California [Member] | Byetta [Member]
Loss Contingency, Number of Lawsuits	100
Loss Contingency, Number of Plaintiffs	485