Segments (Revenue by segments) (Details 2) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014		Jun. 30, 2015	Jun. 30, 2014
Revenue
Revenue	$ 20,813	$ 24,047	[1]	$ 40,403	$ 46,283	[1]
Total Segments
Revenue
Revenue	20,778	23,955		40,301	46,083
Total reportable segments | Total Segments
Revenue
Revenue	22,693	26,074		44,184	50,301
Eliminations of internal transactions | Total Segments
Revenue
Revenue	(1,915)	(2,119)		(3,883)	(4,218)
Other revenue adjustments
Revenue
Revenue	$ 35	$ 93		$ 102	$ 200

[1] Reclassified to reflect discontinued operations presentation.