Financial Instruments and Fair Value Measurement (Details) (USD $)	Sep. 30, 2013 Recurring basis Fair Value	Dec. 31, 2012 Recurring basis Fair Value	Sep. 30, 2013 Recurring basis Quoted Price in Active Markets for Identical Assets (Level 1)	Dec. 31, 2012 Recurring basis Quoted Price in Active Markets for Identical Assets (Level 1)	Sep. 30, 2013 Recurring basis Significant Other Observable Inputs (Level 2)	Dec. 31, 2012 Recurring basis Significant Other Observable Inputs (Level 2)	Sep. 30, 2013 Recurring basis Significant Unobservable Inputs (Level 3)	Dec. 31, 2012 Recurring basis Significant Unobservable Inputs (Level 3)	Sep. 30, 2013 Gloucester Pharmaceuticals, Inc. Maximum	Sep. 30, 2013 Avila Therapeutics, Inc. Maximum	Mar. 07, 2012 Avila Therapeutics, Inc. Maximum
Fair Value of assets and liabilities
Potential milestone payment									$ 120,000,000.0	$ 595,000,000.0	$ 595,000,000
Assets:
Available-for-sale securities	3,424,300,000	1,809,900,000	422,300,000	300,000	3,002,000,000	1,809,600,000
Cash equivalents	52,000,000	27,000,000			52,000,000	27,000,000
Interest rate swaps		1,700,000				1,700,000
Forward currency contracts		17,800,000				17,800,000
Purchased currency options		2,700,000				2,700,000
Total assets	3,476,300,000	1,859,100,000	422,300,000	300,000	3,054,000,000	1,858,800,000
Liabilities:
Forward currency contracts	(8,900,000)				(8,900,000)
Contingent value rights	(347,900,000)	(277,400,000)	(347,900,000)	(277,400,000)
Written currency options	(300,000)	(5,100,000)			(300,000)	(5,100,000)
Interest rate swaps	(31,500,000)				(31,500,000)
Other acquisition related contingent consideration	(207,000,000)	(198,100,000)					(207,000,000)	(198,100,000)
Total liabilities	$ (595,600,000)	$ (480,600,000)	$ (347,900,000)	$ (277,400,000)	$ (40,700,000)	$ (5,100,000)	$ (207,000,000)	$ (198,100,000)