Capital Stock - Net Income (loss) Per Common Share (Detail) - 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
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ (4,868)	$ 449	$ (9,387)	$ 1,101
Income (loss) from discontinued operations	(732)	56	(864)	(360)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCK	(5,600)	505	(10,251)	741
Income (loss) from continuing operations	(4,868)	449	(9,387)	1,101
Income (loss) from discontinued operations	(732)	56	(864)	(360)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCK	$ (5,600)	$ 505	$ (10,251)	$ 741
Income (loss) from continuing operations, shares	378	385	377	390
Income (loss) from discontinued operations, shares	378	385	377	390
Income (loss) attributable to common stock, shares	378	385	377	390
Stock options and other, shares		2		2
Income (loss) from continuing operations, shares	378	387	377	392
Income (loss) from discontinued operations, shares	378	387	377	392
Income (loss) attributable to common stock, shares	378	387	377	392
Basic income (loss) from continuing operations per share	$ (12.89)	$ 1.17	$ (24.88)	$ 2.83
Basic income(loss) from discontinued operations per share	(1.94)	0.14	(2.29)	(0.93)
Income (loss) attributable to common stock, per share	(14.83)	1.31	(27.17)	1.90
Diluted income (loss) from continuing operations per share	(12.89)	1.17	(24.88)	2.82
Diluted income(loss) from discontinued operations per share	(1.94)	0.14	(2.29)	(0.93)
Income (loss) attributable to common stock, per share	$ (14.83)	$ 1.31	$ (27.17)	$ 1.89