Quarterly Results (Unaudited) - Unaudited Quarterly Results (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 29,328	[1]	$ 20,579	[1]	$ 19,340	[1]	$ 19,741	[1]	$ 25,587	[1]	$ 17,092	[1]	$ 15,704	[1]	$ 16,070	[1]	$ 88,988	$ 74,452	$ 61,093
Income (loss) from operations	591	[1]	(544)	[1]	(15)	[1]	146	[1]	510	[1]	(25)	[1]	79	[1]	181	[1]	178	745	676
Income (loss) before income taxes	429	[1]	(634)	[1]	(27)	[1]	120	[1]	451	[1]	(43)	[1]	17	[1]	81	[1]	(111)	506	544
Benefit (provision) for income taxes	(205)	[1]	205	[1]	(94)	[1]	(73)	[1]	(179)	[1]	12	[1]	(13)	[1]	18	[1]	167	161	428
Net income (loss)	$ 214	[1]	$ (437)	[1]	$ (126)	[1]	$ 108	[1]	$ 239	[1]	$ (41)	[1]	$ (7)	[1]	$ 82	[1]	$ (241)	$ 274	$ (39)
Basic earnings per share	$ 0.46	[1]	$ (0.95)	[1]	$ (0.27)	[1]	$ 0.23	[1]	$ 0.52	[1]	$ (0.09)	[1]	$ (0.02)	[1]	$ 0.18	[1]	$ (0.52)	$ 0.60	$ (0.09)
Diluted earnings per share	$ 0.45	[1]	$ (0.95)	[1]	$ (0.27)	[1]	$ 0.23	[1]	$ 0.51	[1]	$ (0.09)	[1]	$ (0.02)	[1]	$ 0.18	[1]	$ (0.52)	$ 0.59	$ (0.09)
Shares used in computation of earnings per share:
Basic	464	[1]	463	[1]	461	[1]	460	[1]	458	[1]	457	[1]	456	[1]	455	[1]	462	457	453
Diluted	472	[1]	463	[1]	461	[1]	468	[1]	467	[1]	457	[1]	456	[1]	463	[1]	462	465	453

[1] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted-average shares outstanding for each period.