Noncontrolling Interests (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Activity for equity attributable to noncontrolling interests
Beginning Balance		$ 40,082	$ 52,273
Net income (loss)		(1,456)	286	[1]
Dividends paid		(313)	(910)	[1]
Distributions to noncontrolling interests		(16)	(21)
Other	[2]	1,110	(2,620)
Ending Balance		39,407	49,008
Common Stockholders' Equity [Member]
Activity for equity attributable to noncontrolling interests
Beginning Balance		39,762	51,911
Net income (loss)		(1,469)	272
Dividends paid		(313)	(910)
Other		1,109	(2,621)
Ending Balance		39,089	48,652
Noncontrolling Interest [Member]
Activity for equity attributable to noncontrolling interests
Beginning Balance		320	362
Net income (loss)		13	14
Distributions to noncontrolling interests		(16)	(21)
Other			1
Ending Balance		$ 318	$ 356

[1] *Certain amounts have been reclassified to conform to current-period presentation. See Note 16–Cash Flow Information, in the Notes to Consolidated Financial Statements.See Notes to Consolidated Financial Statements.

[2] *Includes components of other comprehensive income (loss), which are disclosed separately in the Consolidated Statement of Comprehensive Income.