Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Principles of Consolidation [Abstract]
Investments accounted for using the equity method, minimum interest (in hundredths)	20.00%
Investments accounted for using the equity method, maximum interest (in hundredths)	50.00%
Equity method investments included in Other assets	$ 25	$ 20
Investments accounted for using the cost method, maximum interest (in hundredths)	20.00%
Shipping and Handling Costs [Abstract]
Shipping and handling costs classified as Selling, general and administrative expenses	$ 1,262	$ 1,250	$ 1,142
Inventories [Abstract]
Approximate percentage of inventories determined using the first-in, first-out (FIFO) method (in hundredths)	80.00%
Minimum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	3 years
Maximum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	15 years
Maximum [Member] | Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated useful life (in years)	40 years