Fair Value Measurements (Major Categories of Financial Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Millions		Mar. 31, 2018		Dec. 31, 2017
Other current assets		$ 125	[1]	$ 497	[2],[3]
Other assets		72	[1]	68	[3]
Other accrued liabilities		122	[1]	44	[2],[3]
Other liabilities		850	[1],[4]	353	[2],[3]
Significant Other Observable Inputs (Level 2) [Member]
Other current assets		125	[1]	197	[2],[3]
Other assets		72	[1]	68	[3]
Other accrued liabilities		122	[1]	42	[2],[3]
Other liabilities		830	[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
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 quoted prices 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 quoted prices for similar assets and liabilities.

[4] At March 31, 2018, other liabilities include contingent consideration that was measured using unobservable (level 3) inputs, in the amount of $20 million.