Segments (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Operating revenue		$ 10,707	$ 10,621	$ 20,095	$ 19,537
Exchanged products | Intersegment Sales/Other
Segment Reporting Information [Line Items]
Operating revenue	[1]	$ (858)	$ (1,524)	$ (1,640)	$ (2,527)

[1] Includes $1.9 billion of deferred income tax expense primarily related to pension obligations that will not be recognized in net income until the pension obligations are fully extinguished.