Fair Value Measurements (Major Categories of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2018		Dec. 31, 2017
Other current assets		$ 189	[1]	$ 497	[2],[3]
Other assets	[3]			68
Other accrued liabilities		50	[1]	44	[2],[3]
Other liabilities		307	[1],[4]	353	[2],[3]
Significant Other Observable Inputs (Level 2) [Member]
Other current assets		189	[1]	197	[2],[3]
Other assets	[3]			68
Other accrued liabilities		50	[1]	42	[2],[3]
Other liabilities		287	[1],[4]	333	[2],[3]
Significant Unobservable Inputs (Level 3) [Member]
Other current assets	[2],[3]			300
Other accrued liabilities	[2],[3]			2
Other liabilities		20	[1],[4]	20	[2],[3]
Other Current Assets [Member]
Contingent consideration				300
Investments [Member]
Other assets	[5]	32
Investments [Member] | Significant Unobservable Inputs (Level 3) [Member]
Other assets	[5]	32
Other Noncurrent Assets [Member]
Other assets	[1]	66
Other Noncurrent Assets [Member] | Significant Other Observable Inputs (Level 2) [Member]
Other assets	[1]	66
Other Accrued Liabilities [Member]
Contingent consideration				2
Other Liabilities [Member]
Contingent consideration		$ 20		$ 20

[1] Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities.

[2] At December 31, 2017, other current assets, other accrued liabilities and other liabilities include contingent consideration that was measured using unobservable (Level 3) inputs, in the amounts of $300 million, $2 million and $20 million, respectively.

[3] Derivative assets and liabilities include foreign exchange contracts which are measured using observable inputs for similar assets and liabilities.

[4] Other liabilities include contingent consideration that was measured using unobservable (Level 3) inputs, in the amount of $20 million.

[5] One of the Company's equity securities was measured using unobservable (Level 3) inputs, in the amount of $32 million.