Financial Instruments - Derivatives, Gains and Losses (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	$ 34	$ 357	$ 830	$ 330
Gain (loss) recognized in earnings attributable to risk being hedged	83	(187)	(267)	(116)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Recognized in OCI	(96)	109	(1,292)	1,059
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Reclassified from AOCI to Earnings	(15)	273	(26)	843
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, (Ineffectiveness) and Amounts Excluded from Effectiveness Testing	24	4	49	10
Gain (loss) on fair value hedges ineffectiveness	(3)	1	1	(2)
Gains and (Losses) excluded from the assessment of hedge effectiveness for fair value hedges	0	0	0	0
Gains and (Losses) associated with underlying exposure that did not occur or was not expected to occur for cash flow hedges	0	0	0	0
Foreign exchange contracts \| Derivative instruments in cash flow hedging relationships
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Recognized in OCI	35	36	(221)	467
Foreign exchange contracts \| Net investment hedge
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Recognized in OCI	(131)	73	(1,071)	592
Cost of financing \| Interest rate contracts \| Derivative instruments in fair value hedging relationships
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	(20)	125	195	145
Gain (loss) recognized in earnings attributable to risk being hedged	40	(99)	(127)	(63)
Interest expense \| Interest rate contracts \| Derivative instruments in fair value hedging relationships
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	(21)	112	214	121
Gain (loss) recognized in earnings attributable to risk being hedged	43	(88)	(140)	(53)
Interest expense \| Interest rate contracts \| Derivative instruments in cash flow hedging relationships
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Reclassified from AOCI to Earnings	(7)	0	(17)	0
Interest expense \| Foreign exchange contracts \| Net investment hedge
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, (Ineffectiveness) and Amounts Excluded from Effectiveness Testing	25	4	51	6
SG&A expense \| Foreign exchange contracts \| Derivative instruments in cash flow hedging relationships
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Reclassified from AOCI to Earnings	2	43	(1)	124
SG&A expense \| Equity contracts \| Derivative instruments not designated as hedging instruments
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	45	(81)	87	(63)
Other (income) and expense \| Interest rate contracts \| Derivative instruments not designated as hedging instruments
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	0	0	0	(2)
Other (income) and expense \| Foreign exchange contracts \| Derivative instruments in cash flow hedging relationships
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Reclassified from AOCI to Earnings	(6)	185	6	565
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, (Ineffectiveness) and Amounts Excluded from Effectiveness Testing	(1)	0	(1)	4
Other (income) and expense \| Foreign exchange contracts \| Derivative instruments not designated as hedging instruments
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	30	208	335	134
Other (income) and expense \| Equity contracts \| Derivative instruments not designated as hedging instruments
Derivative Instruments, Gain (Loss)
Amount of gain (loss) recognized in earnings on derivatives	0	(8)	(1)	(5)
Cost of sales \| Foreign exchange contracts \| Derivative instruments in cash flow hedging relationships
Derivative Instruments, Gain (Loss)
Gain (Loss) Recognized in Earnings and Other Comprehensive Income, Effective Portion Reclassified from AOCI to Earnings	$ (4)	$ 46	$ (14)	$ 154

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

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The amount of net gain (loss) reclassified into earnings in the period when cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

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Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

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