Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Basic EPS
Income (loss) from continuing operations	$ 180	$ 1,161	$ (35)	$ 2,298
Less: Income from continuing operations attributable to noncontrolling interest		(3)		(5)
Income from continuing operations attributable to common stock	180	1,158	(35)	2,293
Discontinued operations, net	(4)	273	(7)	528
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCK	176	1,431	(42)	2,821
Less: Net income allocated to participating securities		(3)		(4)
Net income attributable to common stock, net of participating securities	$ 176	$ 1,428	$ (42)	$ 2,817
Weighted average number of basic shares	766.4	782.6	768.0	786.9
Basic EPS (in dollars per share)	$ 0.23	$ 1.83	$ (0.05)	$ 3.58
Diluted EPS
Net income attributable to common stock, net of participating securities	$ 176	$ 1,428	$ (42)	$ 2,817
Weighted average number of basic shares	766.4	782.6	768.0	786.9
Dilutive effect of potentially dilutive securities (in shares)	0.2	0.3		0.3
Total diluted weighted average common shares	766.6	782.9	768.0	787.2
Diluted EPS (in dollars per share)	$ 0.23	$ 1.82	$ (0.05)	$ 3.58