Intangible Assets (Summary of Intangible Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Gross acquired intangible assets	$ 37,923.3	$ 37,806.3
Accumulated amortization	(4,877.2)	(3,108.8)
Intangible assets, net	33,046.1	34,697.5	$ 9,173.3
Currently marketed products
Finite-Lived Intangible Assets [Line Items]
Gross acquired intangible assets	31,973.5	31,217.5
Accumulated amortization	(4,549.2)	(2,908.6)
Intangible assets, net	27,424.3	28,308.9
IPR&D
Finite-Lived Intangible Assets [Line Items]
Gross acquired intangible assets	5,113.9	5,746.6
Accumulated amortization	0.0	0.0
Intangible assets, net	5,113.9	5,746.6
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross acquired intangible assets	835.9	842.2
Accumulated amortization	(328.0)	(200.2)
Intangible assets, net	$ 507.9	$ 642.0