Supplemental Equity and Comprehensive Income Information - Reclass AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Selling, general and administrative expenses	$ 1,493	$ 1,564
Net of tax	(35)	(61)
Gains (losses) associated with defined benefit pension and postretirement plans amortization
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Prior service benefit	23	18
Net actuarial loss	(126)	(159)
Curtailments/Settlements		17
Total before tax	(103)	(124)
Tax effect	34	46
Net of tax	(69)	(78)
Cash flow hedging instruments gains (losses)
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Total before tax	52	27
Tax effect	(18)	(10)
Net of tax	34	17
Cash flow hedging instruments gains (losses) | Foreign currency forward/option contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Cost of sales	53	30
Cash flow hedging instruments gains (losses) | Commodity price swap contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Cost of sales		(2)
Cash flow hedging instruments gains (losses) | Interest rate swap contracts
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense	$ (1)	$ (1)