Shareowners' Equity and Noncontrolling Interest Stockholders' Equity and Noncontrolling Interest (Changes in ownership interests in subsidiaries) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Equity [Abstract]
Net Income (Loss) Attributable to Parent	$ 1,362	$ 1,854	$ 4,330	$ 4,747
Increase in common stock for sale of subsidiary shares	1	0	24	4
Decrease in common stock for purchase of subsidiary shares	0	24	12	37
Net income attributable to common shareowners after transfers to noncontrolling interests	$ 1,363	$ 1,830	$ 4,342	$ 4,714