Stockholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of Common Stock, Additional Paid in Capital and Common Stock Held in Treasury
Shares issued for stock options, shares	4,500,000
Common Stock
Summary of Common Stock, Additional Paid in Capital and Common Stock Held in Treasury
Beginning Balance, shares	549,600,000	542,500,000	538,500,000
Beginning Balance, amount	$ 5	$ 5	$ 5
Shares issued for stock options, shares	400,000	6,300,000	3,900,000
Shares issued for stock options, amount	1
Shares issued for stock compensation and vesting of restricted stock, shares		800,000	100,000
Ending Balance, shares	550,000,000	549,600,000	542,500,000
Ending Balance, amount	6	5	5
Authorized Ending Balance	700,000,000
Additional Paid-in Capital
Summary of Common Stock, Additional Paid in Capital and Common Stock Held in Treasury
Beginning Balance, amount	1,012	686	461
Shares issued for stock options, amount	9	285	151
Shares withheld for Taxes, Value		1
Shares issued for stock compensation and vesting of restricted stock, amount	(28)	(10)	2
Stock compensation expense	36	54	56
Noncontrolling interest	(8)	(22)
Tax benefits related to stock options	23	14	13
Tax benefits related to defined contribution plans	2	4	3
Ending Balance, amount	1,046	1,012	686
Common Stock Held in Treasury
Summary of Common Stock, Additional Paid in Capital and Common Stock Held in Treasury
Beginning Balance, shares	94,500,000	58,900,000	40,800,000
Beginning Balance, amount	(4,722)	(2,692)	(1,741)
Shares issued for stock options, shares	4,000,000
Shares issued for stock options, amount	198
Shares withheld for taxes, shares	(200,000)	(300,000)
Shares withheld for Taxes, Value	(11)	(19)
Shares issued for stock compensation and vesting of restricted stock, shares	600,000	200,000
Shares issued for stock compensation and vesting of restricted stock, amount	28	9	(1)
Stock compensation expense	1
Repurchases of common stock, shares	(29,700,000)	(35,500,000)	(18,100,000)
Repurchases of common stock, amount	(2,170)	(2,020)	(950)
Ending Balance, shares	119,800,000	94,500,000	58,900,000
Ending Balance, amount	$ (6,676)	$ (4,722)	$ (2,692)