Borrowings and Capital Lease (Narrative) (Details)	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Nov. 02, 2015 USD ($) facility	Dec. 12, 2014 USD ($)
Line of Credit Facility [Line Items]
Repayment of lines of credit	$ 5,664,500,000	$ 14,632,900,000
Capital lease obligation	349,100,000
November 2015 Facilities Agreement
Line of Credit Facility [Line Items]
Facility amount outstanding	2,000,000,000			$ 5,600,000,000
Number of amortizing credit facilities | facility				3
November 2015 Facility A | November 2015 Facilities Agreement
Line of Credit Facility [Line Items]
Repayment of lines of credit	400,000,000
November 2015 Facility B | November 2015 Facilities Agreement
Line of Credit Facility [Line Items]
Repayment of lines of credit	2,200,000,000
November 2015 Facility C | November 2015 Facilities Agreement
Line of Credit Facility [Line Items]
Facility amount outstanding	2,000,000,000
Repayment of lines of credit	400,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Borrowings under the Facilities Agreement	1,050,000,000		$ 450,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Aggregate amount					$ 2,100,000,000.0
Swingline Facility					$ 250,000,000
Baxalta
Line of Credit Facility [Line Items]
Aggregate amount	5,000,000,000
Shire Acquisitions Investment Ireland Designated Activity Company | Senior Notes
Line of Credit Facility [Line Items]
Aggregate amount	12,100,000,000
Deferred financing costs	$ 52,300,000