Fair Value Measurement (Assets and Liabilities Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Change in the Fair Value of Contigent Consideration Receivable
Balance at beginning of period	$ 36.1	$ 38.3
Initial recognition of contingent consideration receivable	33.6	0
(Loss)/gain recognized in the income statement (within Gain on sale of product rights) due to change in fair value during the period	(7.1)	5.4
Reclassification of amounts due to Other receivables within Other current assets	(4.0)	(5.0)
Amounts recorded to other comprehensive income (within foreign currency translation adjustments)	0.8	(1.0)
Balance at end of period	59.4	37.7
Change in the Fair Value of Contigent Consideration Payable
Balance at beginning of period	405.9	136.4
Initial recognition of contingent consideration payable	10.0	233.8
Change in fair value during the period with the corresponding adjustment recognized as a gain/(loss) in the income statement (within Integration and acquisition costs)	(59.2)	1.8
Reclassification of amounts to Other current liabilities	(2.4)	(5.8)
Change in fair value during the period with corresponding adjustment to the associated intangible asset	(4.0)	0
Balance at end of period	$ 350.3	$ 366.2