Segmental Reporting (Revenue by Product) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Revenue from External Customer [Line Items]
Product sales	$ 1,627.3	$ 1,423.2
VYVANSE
Revenue from External Customer [Line Items]
Product sales	509.2	416.8
CINRYZE
Revenue from External Customer [Line Items]
Product sales	164.2	148.1
LIALDA/MEZAVANT
Revenue from External Customer [Line Items]
Product sales	168.0	148.5
ADDERALL XR
Revenue from External Customer [Line Items]
Product sales	98.8	95.7
INTUNIV
Revenue from External Customer [Line Items]
Product sales	10.2	17.4
PENTASA
Revenue from External Customer [Line Items]
Product sales	64.0	78.7
FOSRENOL
Revenue from External Customer [Line Items]
Product sales	37.7	44.1
XAGRID
Revenue from External Customer [Line Items]
Product sales	28.3	25.3
Other Products
Revenue from External Customer [Line Items]
Product sales	30.5	32.3
REPLAGAL
Revenue from External Customer [Line Items]
Product sales	103.2	97.5
ELAPRASE
Revenue from External Customer [Line Items]
Product sales	123.6	125.0
VPRIV
Revenue from External Customer [Line Items]
Product sales	83.6	86.4
FIRAZYR
Revenue from External Customer [Line Items]
Product sales	128.3	92.5
GATTEX/REVESTIVE
Revenue from External Customer [Line Items]
Product sales	51.7	14.9
NATPARA
Revenue from External Customer [Line Items]
Product sales	15.6	0.0
KALBITOR
Revenue from External Customer [Line Items]
Product sales	$ 10.4	$ 0.0