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]
Total Equity, beginning of period at Dec. 31, 2011		$ 7,994	$ 92	$ 3,188	$ (787)	$ 10,787	$ (5,286)
Effect of issuing stock for employee benefit plans, Additional Paid In Capital				80
Effect of issuing stock for employee benefit plans, Retained Earnings						(24)
Effect of issuing stock for employee benefit plans, Treasury Stock							86
Effect of issuing stock for employee benefit plans, Total Equity		142
Other comprehensive income (loss) attributable to Parent	65	65			65
Shareholders' net income	371	371				371
Net income	371
Common dividends declared (per share: $0.04)		(11)				(11)
Repurchase of common stock		0
Total Equity, end of period at Mar. 31, 2012		8,561	92	3,268	(722)	11,123	(5,200)
Redeemable Noncontrolling interest, Beginning Balance at Dec. 31, 2012	114
Total Equity, beginning of period at Dec. 31, 2012		9,769	92	3,295	(671)	12,330	(5,277)
Effect of issuing stock for employee benefit plans, Additional Paid In Capital				10
Effect of issuing stock for employee benefit plans, Retained Earnings						(48)
Effect of issuing stock for employee benefit plans, Treasury Stock							65
Effect of issuing stock for employee benefit plans, Total Equity		27
Other comprehensive income (loss) attributable to Parent	(85)	(85)			(85)
Shareholders' net income	57	57				57
Net income	59
Common dividends declared (per share: $0.04)		(11)				(11)
Repurchase of common stock		(97)					(97)
Increase (Decrease) in Temporary Equity [Roll Forward]
Reedemable Noncontrolling interest, Other comprehensive income	(3)
Reedeemable Noncontrolling Interest, Net income	2
Redeemable Noncontrolling interest, Ending Balance at Mar. 31, 2013	113
Total Equity, end of period at Mar. 31, 2013		$ 9,660	$ 92	$ 3,305	$ (756)	$ 12,328	$ (5,309)