Stockholders' Equity (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	50,000,000	50,000,000
Common Stock, Shares Authorized	2,000,000,000	2,000,000,000
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Treasury Stock, Shares	238,000,000	187,000,000
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 660,000,000
Stock Repurchase Program, Authorized Amount	1,000,000,000		1,000,000,000
Stock Repurchase Program, Number of Shares Authorized to be Repurchased			37,000,000
Stock Repurchased During Period, Shares	51,000,000	105,000,000	82,000,000
Payments for Repurchase of Common Stock	$ 500,000,000	$ 600,000,000	$ 492,000,000