Financial Instruments Fair Value of Derivatives (Details) - USD ($) $ in Millions		Sep. 30, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset, Gross		$ 55	$ 46
Derivative Asset, Counterparty and Cash Collateral Netting	[1]	(39)	(37)
Derivative Asset, Net		16	9
Derivative Liability, Gross		54	79
Derivative Liability, Counterparty and Cash Collateral Netting	[1]	(18)	(32)
Derivative Liability, Net		36	47
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Other Current Assets [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Asset, Gross		55	46
Derivative Asset, Counterparty and Cash Collateral Netting	[1]	(39)	(37)
Derivative Asset, Net		16	9
Not Designated as Hedging Instrument [Member] | Foreign Exchange Contract [Member] | Accrued and Other Current Liabilities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Liability, Gross		54	79
Derivative Liability, Counterparty and Cash Collateral Netting	[1]	(18)	(32)
Derivative Liability, Net		$ 36	$ 47

[1] Counterparty and cash collateral amounts represent the estimated net settlement amount when applying netting and set-off rights included in master netting arrangements between the company and its counterparties and the payable or receivable for cash collateral held or placed with the same counterparty.