Segmental Reporting (Revenue by Product) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenue from External Customer [Line Items]
Product sales	$ 4,406.7	$ 3,950.2	$ 3,128.2
Specialty Pharmaceuticals
Revenue from External Customer [Line Items]
Product sales	2,834.9	2,615.6	2,219.2
Specialty Pharmaceuticals | VYVANSE
Revenue from External Customer [Line Items]
Product sales	1,029.8	805.0	634.2
Specialty Pharmaceuticals | ADDERALL XR
Revenue from External Customer [Line Items]
Product sales	429.0	532.8	360.8
Specialty Pharmaceuticals | INTUNIV
Revenue from External Customer [Line Items]
Product sales	287.8	223.0	165.9
Specialty Pharmaceuticals | EQUASYM
Revenue from External Customer [Line Items]
Product sales	29.2	19.9	22.0
Specialty Pharmaceuticals | DAYTRANA
Revenue from External Customer [Line Items]
Product sales	0	0	49.4
Specialty Pharmaceuticals | LIALDA and MEZAVANT
Revenue from External Customer [Line Items]
Product sales	399.9	372.1	293.4
Specialty Pharmaceuticals | PENTASA
Revenue from External Customer [Line Items]
Product sales	265.8	251.4	235.9
Specialty Pharmaceuticals | RESOLOR
Revenue from External Customer [Line Items]
Product sales	11.8	6.1	0.3
Specialty Pharmaceuticals | FOSRENOL
Revenue from External Customer [Line Items]
Product sales	172.0	166.9	182.1
Specialty Pharmaceuticals | XAGRID
Revenue from External Customer [Line Items]
Product sales	97.2	90.6	87.3
Specialty Pharmaceuticals | Other Products
Revenue from External Customer [Line Items]
Product sales	112.4	147.8	187.9
Human Genetic Therapies
Revenue from External Customer [Line Items]
Product sales	1,418.0	1,229.3	909.0
Human Genetic Therapies | REPLAGAL
Revenue from External Customer [Line Items]
Product sales	497.5	475.2	351.3
Human Genetic Therapies | ELAPRASE
Revenue from External Customer [Line Items]
Product sales	497.6	464.9	403.6
Human Genetic Therapies | VPRIV
Revenue from External Customer [Line Items]
Product sales	306.6	256.2	143.0
Human Genetic Therapies | FIRAZYR
Revenue from External Customer [Line Items]
Product sales	116.3	33.0	11.1
Regenerative Medicine
Revenue from External Customer [Line Items]
Product sales	153.8	105.3	0
Regenerative Medicine | DERMAGRAFT
Revenue from External Customer [Line Items]
Product sales	$ 153.8	$ 105.3	$ 0