Financial Information By Industry Segment And Geographic Area (Information By Geographic Area, Net Sales) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Net sales		$ 5,711	$ 5,517	$ 5,383	$ 5,132	$ 5,000	$ 4,864	$ 4,914	$ 4,717	$ 21,743	[1]	$ 19,495	[1]	$ 20,675	[1]
Operating Segments [Member] | United States (h)
Segment Reporting Information [Line Items]
Net sales	[1],[2]									16,247		14,363		14,875
Operating Segments [Member] | EMEA
Segment Reporting Information [Line Items]
Net sales	[1]									3,129		2,852		2,759
Operating Segments [Member] | Pacific Rim and Asia
Segment Reporting Information [Line Items]
Net sales	[1]									625		699		1,501
Operating Segments [Member] | Americas, other than U.S.
Segment Reporting Information [Line Items]
Net sales	[1]									$ 1,742		$ 1,581		$ 1,540

[1] Net sales are attributed to countries based on the location of the seller.

[2] Export sales to unaffiliated customers were $2.9 billion in 2017, $1.8 billion in 2016 and $1.8 billion in 2015.