Shareholders Equity (Details 2) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012
Treasury Stock [Roll Forward]
Treasury Stock, Shares, Beginning (shares)	14,924
Treasury Stock, Shares, Ending (shares)	16,012
Treasury Stock, Value, Beginning	$ 104
Purchases	172		718
Cancellation of treasury stock	0		0
Treasury Stock, Value, Ending	162
Treasury Stock
Treasury Stock [Roll Forward]
Treasury Stock, Shares, Beginning (shares)	14,924
Purchases (in shares)	17,372	[1]
Cancellations (in shares)	(16,284)
Treasury Stock, Shares, Ending (shares)	16,012
Treasury Stock, Value, Beginning	104
Purchases	172	[1]	718
Cancellation of treasury stock	(114)		(481)
Treasury Stock, Value, Ending	$ 162

[1] (1)Includes associated fees.