Statement of Changes in Total Equity (USD $) In Millions, unless otherwise specified	Total	Shareholders' Equity [Member]	Common Stock [Member]	Additional Paid In Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2011	$ 0
Total Equity, beginning of period at Dec. 31, 2011	7,994	7,994	92	3,188	(787)	10,787	(5,286)	0
Increase (Decrease) In Stockholders Equity [Roll Forward]
Effect of issuing stock for employee benefit plans	255	255		107		(69)	217
Other comprehensive income (loss)	116	116			116
Net income	1,623	1,623				1,623
Common dividends declared (per share: $0.04)	(11)	(11)				(11)
Repurchase of common stock	(208)	(208)					(208)
Redeemable Noncontrolling Interest [Roll Forward]
Effects of acquisition of joint venture	111
Other comprehensive income (loss)	2
Net income	1
Ending Balance at Dec. 31, 2012	114
Total Equity, end of period at Dec. 31, 2012	9,769	9,769	92	3,295	(671)	12,330	(5,277)	0
Increase (Decrease) In Stockholders Equity [Roll Forward]
Effect of issuing stock for employee benefit plans	185	185		61		(119)	243
Effects of acquisition of joint venture	14							14
Other comprehensive income (loss)	151	151			151
Net income	1,476	1,476				1,476
Common dividends declared (per share: $0.04)	(11)	(11)				(11)
Repurchase of common stock	(1,003)	(1,003)					(1,003)
Redeemable Noncontrolling Interest [Roll Forward]
Effects of acquisition of joint venture	6
Other comprehensive income (loss)	(19)
Net income	2
Distribution to noncontrolling interest	(7)
Ending Balance at Dec. 31, 2013	96
Total Equity, end of period at Dec. 31, 2013	10,581	10,567	92	3,356	(520)	13,676	(6,037)	14
Increase (Decrease) In Stockholders Equity [Roll Forward]
Effect of issuing stock for employee benefit plans	165	165		69		(124)	220
Other comprehensive income (loss)	(415)	(416)			(416)			1
Net income	2,093	2,102				2,102		(9)
Common dividends declared (per share: $0.04)	(11)	(11)				(11)
Repurchase of common stock	(1,629)	(1,629)					(1,629)
Retirement of treasury stock	0	0	(18)	(652)		(5,354)	6,024
Capital contribution by noncontrolling interest	5	(4)		(4)				9
Redeemable Noncontrolling Interest [Roll Forward]
Other comprehensive income (loss)	(7)
Net income	1
Capital contribution by noncontrolling interest	4
Distribution to noncontrolling interest	(4)
Ending Balance at Dec. 31, 2014	90
Total Equity, end of period at Dec. 31, 2014	$ 10,789	$ 10,774	$ 74	$ 2,769	$ (936)	$ 10,289	$ (1,422)	$ 15