Integration and Acquisition Costs (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Integration and acquisition costs (credits)	$ 237.0	$ 284.5	$ 696.7	$ 738.6
Baxalta
Business Acquisition [Line Items]
Integration and acquisition costs (credits)	238.1		548.6
Employee severance and acceleration of stock compensation
Business Acquisition [Line Items]
Integration and acquisition costs (credits)		123.9		389.4
Employee severance and acceleration of stock compensation | Baxalta
Business Acquisition [Line Items]
Integration costs	60.2		177.4
Third-party professional fees
Business Acquisition [Line Items]
Integration and acquisition costs (credits)		65.8		155.0
Third-party professional fees | Baxalta
Business Acquisition [Line Items]
Integration costs	28.4		114.0
Facility consolidations | Baxalta
Business Acquisition [Line Items]
Integration costs	29.7		71.4
Asset impairments | Baxalta
Business Acquisition [Line Items]
Integration costs	114.1		147.8
Contract terminations
Business Acquisition [Line Items]
Integration and acquisition costs (credits)		43.9		56.6
Acquisition-related costs (including legal, investment banking, and other transaction-related fees)
Business Acquisition [Line Items]
Integration and acquisition costs (credits)		6.8		132.4
Change in fair value of contingent consideration
Business Acquisition [Line Items]
Integration and acquisition costs (credits)	$ 3.4	$ 18.2	$ 144.3	$ (26.9)