Segmental Reporting (Revenue by Product) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue from External Customer [Line Items]
Product sales	$ 5,830.4	$ 4,757.5	$ 4,252.9
VYVANSE
Revenue from External Customer [Line Items]
Product sales	1,449.0	1,227.8	1,029.8
ADDERALL XR
Revenue from External Customer [Line Items]
Product sales	383.2	375.4	429.0
INTUNIV
Revenue from External Customer [Line Items]
Product sales	327.2	334.9	287.8
LIALDA and MEZAVANT
Revenue from External Customer [Line Items]
Product sales	633.8	528.9	399.9
PENTASA
Revenue from External Customer [Line Items]
Product sales	289.7	280.6	265.8
FOSRENOL
Revenue from External Customer [Line Items]
Product sales	183.0	183.4	172.0
XAGRID
Revenue from External Customer [Line Items]
Product sales	108.5	99.4	97.2
Other Products
Revenue from External Customer [Line Items]
Product sales	128.9	136.1	153.4
REPLAGAL
Revenue from External Customer [Line Items]
Product sales	500.4	467.9	497.5
ELAPRASE
Revenue from External Customer [Line Items]
Product sales	592.8	545.6	497.6
VPRIV
Revenue from External Customer [Line Items]
Product sales	366.7	342.7	306.6
FIRAZYR
Revenue from External Customer [Line Items]
Product sales	364.2	234.8	116.3
CINRYZE
Revenue from External Customer [Line Items]
Product sales	$ 503.0	$ 0	$ 0