Goodwill and Intangible Assets (Components of Intangible Assets) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2016	Dec. 31, 2018
Intangible Assets by Major Class [Line Items]
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	$ 29.5	$ 30.0
Finite-lived intangible assets, original cost	20,232.7			$ 20,264.1
Finite-lived intangible assets, accumulated amortization	7,521.2			7,225.1
Finite-lived intangible assets, net book value	12,711.5			13,039.0
In-process research and development	244.0			625.6
Intangible assets, gross, excluding goodwill	20,476.7			20,889.7
Intangible assets, net book value, excluding goodwill	$ 12,955.5			$ 13,664.6
Patents and technologies
Intangible Assets by Major Class [Line Items]
Finite-lived intangible assets, estimated useful life, in years	15 years		15 years