Stockholders' Equity Stockholders' Equity (Details) (USD $) Share data in Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Stockholders' Equity Attributable to Parent [Abstract]
Stock Repurchased During Period, Shares	14
Payments for Repurchase of Common Stock	$ 500,000,000	$ 500,000,000	$ 0
Stock Repurchase Program, Authorized Amount	$ 5,000,000,000