Fair Value Measurements (Aggregate Fair Value of Derivative Financial Instruments, Debt and Contingent Consideration) (Details) $ in Millions	Sep. 30, 2017 USD ($)
Quoted Prices in Active Markets for Identical Assets/Liabilities (Level 1) [Member]
Assets:
Foreign exchange contracts	$ 0
Total assets	0
Liabilities:
Debt	32,961
Foreign exchange contracts	0
Total liabilities	32,961
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Foreign exchange contracts	255
Total assets	255
Liabilities:
Debt	172
Foreign exchange contracts	1,067
Total liabilities	1,239
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Foreign exchange contracts	0
Total assets	0
Liabilities:
Debt	0
Foreign exchange contracts	0
Total liabilities	0
Fair Value [Member]
Assets:
Foreign exchange contracts	255
Total assets	255
Liabilities:
Debt	33,133
Foreign exchange contracts	1,067
Total liabilities	$ 34,200